(四)
33. Given the row-reduced echelon form of a matrix A. What is the closest vector to b = [0,3,0, 1]T in the row space of A? (A) [1,1,2,0]T (B) [0,-2,-1,1]T (C) [-1, 2,0, -1]T (D) [-1,2,1,0]T (E) [1,1,3,1]T