(1 point) Suppose A is an 5 X 5 matrix. Select "yes" if the statement is always true, "no" if the statement is always false, and "maybe" if the statement is sometimes true and sometimes false. a. If rank A = 4 , then the columns of A form a basis of R5. Choose c b. If A has three pivots, then C01 A is a (two-dimensional) plane. Choose c. If A has two pivots, then the dimension of Nul A is 2. Choose 3 d. If Ax = 0 has only the trivial solution, then Co] A = R5 . Choose