What role do all antigen-presenting cells (apcs) play?
select one:
a. synthesis of antibodies
b. activation of t cells
c. phagocytosis of pathogens
d. recognition of epitopes

b). activation of T cells

Explanation:

An APC (antigen-presenting cell) can be described as an immune cell, which detects, uptakes, and informs the acquired immune response when an infection takes place. B cells, macrophages, and dendritic cells are antigen-presenting cells.

These cells play an important role in activation of T cells. T cells are unable to recognize soluble or free antigens and can only recognize antigens processed and presented by carrier molecules, such as MHC molecules.

Presence of MHCII molecules is a defining feature of APCs that process and present antigens to T cells. Hence, all antigen-presenting cells help in activation of T cells.  

Thus, the correct answer is option (b).

the answer to your question is:

c. complementary base-pairing

helicase, i think thats it