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 1 and -3, so their sum is 1 + -3 = -2. Since sum = -p, we have -p = -2, which gives p = 2. The product 1×-3 = -3 also matches the constant term, so the roots are consistent. Therefore the correct answer is 2.