Correct Answer: C

Rationale: The correct answer is C: Increased risk of cardiovascular events. Cardiovascular events such as stroke and myocardial infarction are the most concerning adverse effects of testosterone therapy, especially in older patients.
Choice A, increased risk of breast cancer, is not a common adverse effect of testosterone therapy in males.
Choice B, increased risk of liver dysfunction, is a potential adverse effect but is not the most concerning.
Choice D, increased risk of prostate cancer, is a consideration in patients with a history of prostate cancer or those with prostate carcinoma, not typically in patients receiving testosterone therapy for hypogonadism.

Correct Answer: A

Rationale: The correct answer is A. Raloxifene works by decreasing bone resorption and increasing bone density. This helps in strengthening bones, reducing the risk of fractures, and improving bone health in patients with osteoporosis.
Choice B is incorrect because raloxifene does not directly stimulate the formation of new bone but rather prevents bone loss.
Choice C is incorrect as raloxifene does not primarily affect calcium absorption in the intestines.
Choice D is also incorrect as raloxifene does not primarily decrease the excretion of calcium through the kidneys.

Correct Answer: A

Rationale: The correct factors that contribute to an individual's ability to adapt to stress are age, socioeconomic status, and gender. Age can influence coping mechanisms and resilience. Socioeconomic status can impact access to resources and support systems. Gender differences can also play a role in how individuals experience and manage stress. Ethnicity, while important in other contexts, is not directly mentioned in the provided rationale and is not one of the factors listed as contributing to an individual's ability to adapt to stress.

Correct Answer: B

Rationale: When a patient with active tuberculosis is not responding to antitubercular drug therapy, drug-resistant tuberculosis should be suspected. Drug-resistant tuberculosis occurs when the bacteria causing tuberculosis become resistant to the medications being used.

Choices A, C, and D are incorrect because the scenario described does not align with HIV infection, methicillin-resistant Staphylococcus aureus, or vancomycin-resistant Staphylococcus aureus.

Correct Answer: C

Rationale: Antigens are the correct answer as they are the molecules that trigger the immune response by binding to specific B or T cells. This binding activates these cells, leading to their proliferation and differentiation to fight off the antigen. B cells and T cells are the responders to antigens, not the initiators of clonal selection. Lymphocytes is a broad term encompassing both B and T cells, so it is not the specific factor responsible for initiating clonal selection.