I believe that on the Naive B-cell the antibodies exist as transmembrane proteins. A naive b-cell is a type of b-cell that has not been exposed to an antigen. When exposed it becomes either a memory B cell or a plasma cell that secrete antibodies specific to the antigen that was originally bound.
Answer:
a. Centromere
A centromere is a specialised DNA sequence of a chromosome that links pair of sister chromarids (a dyad)
