During the process of succession, only consumers can enter a developing ecosystem before producers

This statement is false.

Explanation:

Producers (namely mosses and liches) are the first organisms to reenter an ecosystem and are known as "pioneer species". They are proceeded by (in this order) small plants, shrubs, bushes, and climax communities (i.e. large trees). Only then do consumers once again become part of the ecosystem. For all of these reasons, the statement presented in this question is false.

answer: b

coz red blood cells marrow and circulates the body for 120 days.