Determine whether the matrix is elementary. if it is, state the elementary row operation used to produce it. 1 0 0 0 −3 1 0 0 0 0 1 0 0 0 0 1 the matrix is elementary. it can be obtained from the identity matrix by interchanging two rows. the matrix is elementary. it can be obtained from the identity matrix by multiplying a row by a nonzero constant. the matrix is elementary. it can be obtained from the identity matrix by adding a multiple of a row to another row. the matrix is not elementary.