Correct Answer: B

Rationale: The correct answer is B: T cell deficiency. The symptoms described in the case, including low-set ears, a fish-shaped mouth, involuntary rapid muscular contraction, and decreased calcium levels, are indicative of DiGeorge syndrome. This syndrome is characterized by T cell deficiency due to thymic hypoplasia. B cell deficiency (Choice A), combined immunodeficiency (Choice C), and complement deficiency (Choice D) do not align with the clinical presentation and laboratory findings provided in the case. Therefore, T cell deficiency is the most likely diagnosis in this scenario.

Correct Answer: B

Rationale: Cushing's syndrome is characterized by the excessive production of cortisol by the adrenal glands, not growth hormone (Choice A), insulin (Choice C), or ACTH (Choice D). The increased cortisol levels lead to a variety of symptoms associated with Cushing's syndrome.

Correct Answer: C

Rationale: A tension pneumothorax is characterized by a large accumulation of trapped air in the pleural space, creating pressure that affects both the lungs and heart. This condition can lead to life-threatening consequences by shifting mediastinal structures and impairing cardiac function. Treatment involves decompressing the trapped air to relieve the tension. Choices A, B, and D are incorrect as they do not describe the primary pathophysiological mechanism of tension pneumothorax, which is the accumulation of air in the pleural space, not blood, rib fractures, or alveolar fluid accumulation.

Correct Answer: B

Rationale: The correct answer is B. Testosterone gel should be applied to the chest or upper arms and allowed to dry completely before dressing to avoid transfer to others. Applying the gel to the face, neck, genitals, scalp, or back is not recommended as these areas may lead to unintentional transfer to others, inappropriate absorption, or potential side effects. Choice A is incorrect as applying the gel to the face and neck can lead to unwanted transfer. Choice C is incorrect as applying the gel to the genitals is not the recommended site for application. Choice D is incorrect as the scalp and back are not appropriate sites for applying testosterone gel.

Correct Answer: C

Rationale: The correct answer is C: Too much dopamine in the brain. Parkinson's disease is characterized by a deficiency of dopamine in the brain, not an excess. This deficiency leads to the motor symptoms associated with the disease. Choices A, B, and D are incorrect. Mobility and functioning are affected in Parkinson's disease due to the lack of dopamine, not an excess. The liver and kidneys are not directly related to Parkinson's disease. Skeletal muscle flaccidity is not typically a primary symptom of Parkinson's disease, which is more characterized by rigidity and tremors.