What are the roots of the quadratic equation $$21x^{2} - 37x - 28 = 0$$ ?

A

$$\frac{-7}{3}, \frac{4}{7}$$

B

$$\frac{3}{7}, \frac{-7}{4}$$

C

$$\frac{7}{3}, \frac{-4}{7}$$

D

$$\frac{-3}{7}, \frac{7}{4}$$