To divide complex numbers, you multiply by the conjugate. The conjugate is when you change the sign between the two terms in the denominator. Therefore, the conjugate in this one is (3+i)
[tex] \frac{13-i}{3-i} * \frac{3+i}{3+i} [/tex] ← Then, you foil these guys:
[tex] \frac{(13-i)(3+i)}{(3-i)(3+i)} = \frac{40+10i}{10} = 4 + i [/tex] or C
