Dina encoded a secret phrase using matrix multiplication. She multiplied the clear text code for each letter by the matrix cap c is equal to the 2 by 2 matrix, row 1, column 1, negative 2 column 2, 1 row 2, column 1, 3 column 2, negative 1 to get a matrix that represents the encoded text. By which matrix does Dina multiply the encoded text to get the matrix for the clear text code?