If the number of 5-element subsets of the set $$A = \{a_1, a_2, \ldots, a_{20}\}$$ of 20 distinct elements is $$k$$ times the number of 5-element subsets containing $$a_4$$, then $$k$$ is

A

5

B

$$\dfrac{20}{7}$$

C

4

D

$$\dfrac{10}{3}$$