Suppose that A is a 5 x 5 matrix and CA(A) = (X-1)(12 - 1 -6)(12 + 1). Answer the next THREE questions. Question 23 The rank of 21 - A is (a) 5 (b) 4 (c) 3 (d) impossible to determine (e) none of the above Question 24 Let W denote the solution set to the system I1 T1 A = 5 TA TA 15 Which of the following must always be true? (a) W contains exactly only one vector (b) W has infinitely many vectors (c) W has more than one, but only finitely many vectors (d) W contains exactly one nonzero vector (e) none of the above