Which Statement About Class Switching Is True

Which statement about class switching is true?

A) The first class of immunoglobulin a B cell makes is IgG.
B) A DNA deletion in the constant region produces an immunoglobulin with a different function.
C) When class switching occurs, the class of the new immunoglobulin depends on which of the variable region genes is deleted.
D) Class switching produces an immunoglobulin with different antigen specificity.
E) A DNA deletion in the variable region allows a cell making IgA to switch to making IgM.