Shau-uen solve the equation 18.5w+6.5w-2.8w=149.1 Her work is shown below

Step(1)
18.5w+6.5w-2.8w= 149.10
Step(2)
25w-2.8w= 149.1
Step(3)
-2.8w=5.964
Step(4)
W= -2.13
In which step did Shaun make her first error?

A. Step 1
B. Step 2
C. Step 3
D. Step 4