William solved the equation 5 + 14a = 9a - 5, but he is not sure he solved it correctly. His work is shown below. Did he solve it correctly? If not, on which step did William make his first mistake?

Step 1: 5+ 4a = 94 - 5
Step 2. 5+ 5a=.5
Step 3: 5a = 0
Step 4: a=0

A.Step 3
B. Step 2
C. Step 1
D. Step 4
E. William did not make a mistake. ​