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.

Correct Answer: A

Rationale: The correct statement to include in the nurse's teaching is that clomiphene induces ovulation by stimulating the release of gonadotropins, which in turn stimulate the ovaries. Choice B is incorrect because clomiphene does not induce ovulation by inhibiting gonadotropins. Choice C is also incorrect as clomiphene does not suppress ovulation by inhibiting gonadotropins. Choice D is inaccurate as clomiphene does not directly increase progesterone levels to maintain pregnancy.

Correct Answer: C

Rationale: The correct answer is C: An inflammatory process in the testicles. Secondary hypogonadism in males can be caused by various factors, including an inflammatory process in the testicles. Mumps (choice B) can lead to orchitis but is less common in adults. Type 1 diabetes (choice A) is not a common cause of secondary hypogonadism. Testicular trauma (choice D) can cause primary hypogonadism but is less likely to cause secondary hypogonadism.

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: Intravenous amphotericin can cause nephrotoxicity, leading to increased blood urea nitrogen levels. Elevated blood urea nitrogen (BUN) indicates impaired renal function, which is a known adverse effect of amphotericin. Therefore, a BUN level of 60 mg/dL warrants the discontinuation of the antifungal agent. The other options, such as a sodium level of 138 mEq/L, hematocrit of 39%, and AST level of 10 Unit/L, are within normal ranges and not indicative of the need to discontinue amphotericin therapy.