C. p + q = b and D. p . q = c. The two true statements about p and q for a quadratic trinomial of the form x² + bx + c that can be factored as (x + p)(x + q) is p + q = b and p . q = c.
The easiest way to solve this problem is developing the product (x + p)(x + q) to a trinomial quadratic form.
(x + p)(x + q) = x² + qx + px + p.q = x² + (p + q)x + p.q
The equation above has the form x² + bx + c from which we can deduce the coefficients of x² + (p + q)x + p.q as follow:
a = 1, b = p + q, and c = p . q