4. (5%) Which of the following is true?
(A) A linear transformation with codomain Rm is onto if and only if the rank of its standardmatrix is m.
(B) A linear transformation is one-to-one if and only if its null space consists only of the zerovector.
(C) A linear transformation is onto if and only if the columns of its standard matrix form agenerating set for its range.
(D) If the composition UT of two linear transformations T : Rn → Rm and U : RP → Rq isdefined, then m = p must be true and the composition UT is also a linear transformation.
(E) For every invertible linear transformation T, the function