Suppose that A, B, C, D, and E are matrices with the following sizes: A B C D E (3 x 5) (3 x 2) (5 x 1) (1 x 5) (2x3) Determine whether the matrix expression E(6B + A) is defined. Matrix is not defined. Enter the size of the resulting matrix (enter 'NA' in each box if undefined). E(6B + A) is a ( X