Answer:
option (b) is correct.
First step to solve for deriving the quadratic formula from the quadratic equation is completing the square.
Step-by-step explanation:
Given : the quadratic equation 
We have to find the first step for deriving the quadratic formula from the quadratic equation.
Quadratic formula is given by 
Consider the given quadratic equation
Divide the equation by a, we get,
Take
to other side, we get,
Add
to both side, we get,
Thus, the left side is in the form of 
On solving, we get,

Then solve for x , we get quadratic formula 
Thus, first step to solve for deriving the quadratic formula from the quadratic equation is completing the square.
Thus, option (b) is correct.