Answer:
Option b - Subtract
Step-by-step explanation:
Given : Expression
To find : Which operation should be completed first in the expression below?
Solution :
P - Parentheses
E - Exponent
D - Divide
M - Multiplication
A - Addition
S - Subtraction
In the first step we solve the bracket in the expression
So, we do subtraction i.e. 12-8=4
Therefore, option b is correct.