We have to solve the equation

In order to solve it for x, subtract 3/x to both sides


Multiply both sides by LCM

On simplifying, we get

To check the extraneous solution, we plugging this value of x in the given equation and check if it satisfies or not



This is true. Hence, x=12 is a solution (non-extraneous) to the given equation.
A is the correct option.