Correct Answer: A

Rationale: Depression is the most common psychogenic disorder among elderly individuals. It can manifest as persistent feelings of sadness, hopelessness, and loss of interest in activities that were once enjoyed. Elderly individuals may also experience changes in appetite, sleep disturbances, and difficulty concentrating. Detecting and addressing depression in the elderly is crucial for their overall well-being and quality of life.

Correct Answer: A

Rationale: Pulse pressure is calculated by subtracting the diastolic pressure from the systolic pressure. In this case, the systolic pressure is 150 and the diastolic pressure is 96. Therefore, the pulse pressure is 150 - 96 = 54. Pulse pressure represents the force generated by the heart with each contraction and is an important indicator of cardiovascular health.

Correct Answer: D

Rationale: Leukocytosis is defined as an increase in the total white blood cell count. A normal WBC count typically ranges from 4,500 to 10,000/mm³. A WBC count of 25,000/mm³, as indicated in choice D, is significantly higher than the normal range and clearly indicates leukocytosis.

Correct Answer: B

Rationale: A platelet count is primarily used to assess the risk of bleeding. Platelets play a crucial role in blood clotting, so a low platelet count can lead to an increased risk of bleeding. Monitoring platelet levels helps healthcare providers evaluate a patient's ability to form clots and manage bleeding.

Correct Answer: A

Rationale: Proper hand washing for 30 seconds is recommended after routine patient contact as it effectively removes pathogens. This duration ensures thorough cleaning without excessive time consumption, promoting infection control and prevention.