Correct Answer: A

Rationale: The correct answer is A: Active artificial immunity. This is because the person's immune system is actively stimulated by the vaccine to produce antibodies against Covid-19. It is considered artificial because it is acquired through vaccination rather than natural exposure to the disease.
B: Active natural immunity is incorrect because it refers to immunity acquired through natural exposure to the disease.
C: Passive natural immunity is incorrect because it refers to temporary immunity passed from mother to baby through breast milk or placenta.
D: Passive artificial immunity is incorrect because it refers to receiving pre-formed antibodies, such as through an injection of antibodies rather than the body producing them itself.

Correct Answer: C

Rationale: The correct answer is C: Meningitis. The patient's symptoms of severe headache, photophobia, neck stiffness, nuchal rigidity, and positive Kernig and Brudzinski signs are classic signs of meningitis. Meningitis is an inflammation of the meninges surrounding the brain and spinal cord, leading to these specific neurological symptoms. Migraine headache (
A) typically presents with a throbbing headache, nausea, and sensitivity to light and sound, but does not typically cause neck stiffness or positive meningeal signs. Cluster headache (
B) is characterized by severe unilateral headache with autonomic symptoms like tearing or nasal congestion, but does not typically cause neck stiffness or positive meningeal signs. Subarachnoid hemorrhage (
D) presents with sudden severe headache often described as "the worst headache of my life," and may cause neck stiffness, but typically does not present with photophobia or positive meningeal signs like Kernig and Brudzinski signs.

Correct Answer: B

Rationale: The correct answer is B: Disseminated intravascular coagulation (DI
C). In DIC, there is widespread activation of coagulation leading to consumption of clotting factors, resulting in prolonged PT and aPTT, low fibrinogen levels, and elevated D-dimer. This pattern matches the laboratory findings in the patient. In liver cirrhosis (choice
A), there is a decrease in clotting factors synthesis, leading to prolonged PT but not aPTT. Hemophilia A (choice
C) is a genetic disorder that affects specific clotting factors, typically leading to prolonged aPTT but not PT. Vitamin K deficiency (choice
D) impairs the synthesis of clotting factors, leading to prolonged PT but not aPTT and low levels of factors II, VII, IX, and X.

Correct Answer: A

Rationale: The correct answer is A: Empiric antibiotic therapy directed against common pathogens. This is recommended for managing PID because it helps treat the infection and prevent complications. Antibiotics target the underlying bacterial infection causing PID. Surgical exploration (
B) is not the initial treatment for PID. Hormonal therapy (
C) is not indicated for PID management. Symptomatic treatment with NSAIDs (
D) can help with pain but does not address the infection itself.

Correct Answer: D

Rationale: The correct answer is D: Feeling of hopelessness. Adolescents who feel hopeless are at a higher risk of attempting suicide due to a lack of belief in positive outcomes. This feeling can lead to a sense of being trapped and unable to see a way out. Depressed mood (
A) can contribute to suicide risk, but specifically feeling hopeless is a more direct predictor. Feeling of euphoria (
B) and joyful mood (
C) are actually less likely to be associated with suicide attempts, as they may temporarily mask underlying issues or provide a sense of distraction. Hopelessness is a key psychological factor that can lead to suicidal thoughts and behaviors in adolescents.