Women with urinary tract infections caused by E. coli are generally treated with a course of antibiotics. A common complication of the antibiotic treatment is the occurrence of a vaginal yeast infection caused by Candida albicans, an organism that is normally present in very low numbers in the human vaginal tract. This complication occurs because:

Correct Answer: D

Rationale: Antibiotics disrupt commensal bacteria, allowing Candida overgrowth ; epithelium damage , adhesion , or selective killing don't explain this.

Correct Answer: A

Rationale: Innate behaviors are genetically determined and consistent across a species, not influenced by sociobiology or the environment in their basic execution.

Correct Answer: A

Rationale: Histamine causes vasodilation, increasing blood flow to the injury site, not blocking pollen responses, converting to histidine, or raising blood pressure.

Correct Answer: D

Rationale: Monoclonal antibodies are identical, binding one antigen, not a mix of different antibodies, making D false; others are true applications.

Correct Answer: B

Rationale: Neutrophils are the most abundant WBCs in blood, excelling in phagocytosis, not antigen presentation (DCs) or viral cell killing (NK cells).