How Is the Central Portion of a T-Cell Receptor Complex

How is the central portion of a T-cell receptor complex functionally analogous to the center of the B-cell receptor complex?

A) It has 2 pieces (chains) , just like a B-cell receptor.
B) Both receptors bind epitopes (small amino acid sections of antigen molecules) .
C) Both bind structures directly on the surface of microbes.
D) Both can be secreted from lymphocytes to bind to pathogens under certain situations.