If a and b are two rational numbers, which expressions are equivalent to a-b? Mark all that apply.

A. a-|-b|, if b>0.
B. a+|-b|, if b>0.
C. a+(-b), if b>0.
D. a-|-b|, if b<0.
E. a+|-b|, if b<0.
F. a+(-b), if b<0