Question

1. where are red blood cells produced?

a. yellow bone marrow
b. red bone marrow
c. lymphatic vessels
d. heart chambers

Explanation:

Red blood cells are produced in the red bone marrow. Yellow bone marrow is mainly for fat storage, lymphatic vessels are part of the lymphatic system (not for RBC production), and heart chambers are for blood pumping, not production. So the correct option is b.

Answer:

b. Red bone marrow