Need some ! will appreciate the fastest answer. thnx in advanced!

1) what do b cells do?
a. cause inflammation
b. make your mucous membranes watery
c. produce antibodies
d. eat dead cells

2) why do doctors recommend that people get a new flu shot every year?
a. the flu virus becomes immune to the vaccine
b. the vaccine wears out over time
c. your body eliminates the vaccine
d. the flu virus changes every year

3) antibodies do which of the following?
a. attach to cells with corresponding antigen
b. engulf and destroy pathogens
c. produce antigens
d. produce immature cells that become b cells

i keep getting a d, so if you could kind of explain it to me as well, that will be great.