The use of complement receptor deficient cells has shown that:
A. normal B cells sample antigen on macrophages and leave it intact.
B. normal B cells sample antigen on macrophages and take part of it.
C. complement receptor-deficient B cells do not sample antigen on macrophages.
D. complement receptor-deficient B cells sample antigen on macrophages and take part of it.
E. Both A and C.
Answer: B