the characteristic of blood types AB is

Correct Answer: A

Rationale: Blood type AB is a universal recipient (general receptor) because it has no antibodies against A, B, or Rh antigens, but it is not a universal donor.

Correct Answer: C

Rationale: HIV's high mutation rate creates drug-resistant strains, complicating eradication, not its RNA genome, rare mutation, or size.

Correct Answer: C

Rationale: Zymosan, a fungal cell wall component, is a PAMP, unlike dsRNA (viral), LPS (bacterial), or CpG (bacterial DNA).

Correct Answer: B

Rationale: Antibodies don't form pores (complement does via MAC); they mediate ADCC, neutralization, opsonization, and complement activation.

Correct Answer: C

Rationale: Activated T cells proliferate in lymph nodes, not blood, before exiting as effector cells.