To find the solutions to this equation, we'll solve it first.
Given equation :
⇒

To isolate our x, we need to square-root both sides of the equation.
⇒

Now, be careful here - when we take the square root of a number, we have two solutions.
So, when we take the square root of x^2, we end up with x. When we square root 144, however, we get the following answers :
↠ x = 12, x = -12 (Options A and D)