A student states, "It seems like helper T cells do a lot more than just 'help' the cellular immunity process". Which response listed below best conveys an aspect of the role of CD4 helper T cells in immunity?
a. Helper T cells are key to the hematopoiesis that produces all the components of the immune system.
b. Without helper T cells, the wrong antibiotics would end up being produced.
c. Without helper T cells, no antigens would be presented
d. Helper T cells play a major role in stimulating and regulating the whole process.

Explanation:

Immune system is the protective system in our body which protects us from microbes and fight against pathogens. There are different type of cells in immune system, helper T cells are one of them. They help in stimulation and regulation of different type of cell like  CD4 and some others,  they are the main cell which helps in fighting against pathogens. so we can say that Helper T cells play a major role in stimulating and regulating the whole process.

b. climate change will cause an increase in biodiversity of all ecosystems.

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