Use Vieta's formula for x² + px + q = 0. For this form, the sum of the roots is -p and the product of the roots is q. The given roots are -3 and 5, so their sum is -3 + 5 = 2. Since sum = -p, we have -p = 2, which gives p = -2. The product -3×5 = -15 also matches the constant term, so the roots are consistent. Therefore the correct answer is -2.