Final answer:
To make the expression x² + 36x + c a perfect square, the value of c should be 324.
Step-by-step explanation:
To make the expression x² + 36x + c a perfect square, we need to find the value of c.
In order for a quadratic expression to be a perfect square, the coefficient of the linear term (the x term) must be twice the square root of the constant term. In this case, the constant term is c, so we need to find a value of c that satisfies the equation 36 = 2√c.
Solving this equation, we find that c = 324. Therefore, the correct answer is B) 324.