Sue solved an equation incorrectly, as shown below:

Step 1: 7x = 28
Step 2: x = 28 − 7
Step 3: x = 21

Which statement best explains why Step 2 is incorrect in Sue's solution?

She did not multiply 28 seven times.
She did not divide 28 by 7.
She did not multiply 28 by 7.
She did not add 7 to 28.