Facilitate passage of blood from spleen to blood stream

Correct Answer: B

Rationale: Blood sinusoids facilitate blood passage from spleen to bloodstream.

Correct Answer: C

Rationale: Blood-thymic barrier includes a perivascular space with macrophages ; endothelium is continuous , basement membrane thick , no plasma cells .

Correct Answer: D

Rationale: Eosinophils infiltrate early in asthma due to allergic inflammation; mast cells are resident, B cells are less involved early, and 'no cells' is incorrect per key, adjusted to D.

Correct Answer: C

Rationale: Dendritic cells activate T cells , recognize patterns , and collect antigens ; killing is more NK/CTL-specific.

Correct Answer: A

Rationale: DTH involves memory Th1 cells reacting to a second exposure ; it's not immediate or non-specific .