B Cell-Receptors Differ from T Cell-Receptors in That ________

B cell-receptors differ from T cell-receptors in that ________.

A) B cell-receptors are comprised of four polypeptides,whereas T cell-receptors are made up of two polypeptides
B) B cell-receptors are immunoglobulins similar to those that are secreted,whereas T cell-receptors are not immunoglobulins and are never secreted
C) T cell-receptors are much smaller than B cell-receptors
D) All of the choices reflect differences between B cell- and T cell-receptors.