The steps below show the incomplete solution to find the value of x for the equation 6x − 2x − 5 = −6 + 21:

Step 1: 6x − 2x − 5 = −6 + 21
Step 2: 6x − 2x − 5 = 15
Step 3: 4x − 5 = 15

Which of these is most likely the next step? (4 points)

4x = 10

4x = 3

4x = 45

4x = 20