The roots of the equation x2 + px + q = 0 are equal if :

On comparing it with ax² + bx + c = 0 , we get a = 1, b = p, c = q
The roots of the equation x² + px + q = 0 are equal if
b² - 4ac = 0
⇒ p² - 4q = 0 ⇒ p² = 4q.
Thus , required answer is option B .