If $$f(x) = x^2 + 5x + p$$ and $$g(x) = x^2 + 3x + q$$ have a common factor $$Q(x)$$, then $$Q(x$$) =

A

$$x + \left(\frac{p - q}{2}\right)$$

B

$$x - \left(\frac{p - q}{2}\right)$$

C

$$x + \left(\frac{p + q}{2}\right)$$

D

$$x - \left(\frac{p + q}{2}\right)$$