B-cells do which of the following things? a. Make antibodies
b. Inhibit Function of other T-cells and B-cells
c. Stay in circulation to speed up response to an antigen the next time
d. Stimulate Function of other T-cells and B-cells
e. Take in and process antigens binding them to MHC protein
f. Attack cells infected by viruses

a. Make antibodies

Explanation:

B-cells is one of the two types of lymphocytes or white blood cells produced in the marrow of the bone (the other being T-cells). B-cells are a part of adaptive or acquired immunity in our body i.e. a learned defense after a pathogen might have penetrated.

B-cells help combat foreign Invaders that make way into the body by producing ANTIBODIES, which are specific to a particular pathogen. Note that, the B-cells learnt to combat based on a previous infection of such pathogen. In response to an antigen, the B-cells produce the plasma cells, which in turn produce the antibodies.

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.