The work of a student to solve a set of equations is shown below: Equation 1: m = 6 + n
Equation 2: 2m = 8 + 8n

Step 1: −2(m) = −2(6 + n)
2m = 8 + 8n
Step 2: −2m = −12 − 2n
2m = 8 + 8n
Step 3: −12 − 2n = 8 + 8n
Step 4: −20 = 10n
Step 5: n = −2
In which step did the student first make an error? (4 points)

a
Step 2

b
Step 3

c
Step 4

d
Step 5