7. (4 MARKS) Let A = 2 be an eigenvalue of an n x 71 matrix A. Which of the following is correct? (a) |2I A| 75 0 (b) 21 A is invertible; (c) The eigenvector of A corresponding to A = 2 is zero. (d) The rank of 2I A is strictly less than n; (8) None of these l