Appendix works in
a. neutralize pepsine
b. store calcium
c. contributes in immunity
d. detoxify poison

c. contributes in immunity

Explanation:

The mass of the lymphatic tissues that lack any capsule is known as lymphatic nodules. The lymphatic nodules are scattered in mucous membranes that line the various tracts.

The appendix has an aggregation of lymphatic nodules. The lymphatic nodules of the appendix contain immune cells to protect against diseases or infection. It prevents any possible entry of pathogen and subsequent infection through digestive system.

it is called the mitotic spindle