A bag contains 20 red and green tennis balls. of which 8 are marked 'used' and 12 are red. If the probability of picking a green marked 'used' ball is 1/5, the probability of picking a reel unmarked ball from the bag is

A

$$\frac{2}{5}$$

B

$$\frac{3}{5}$$

C

$$\frac{4}{5}$$

D

$$\frac{3}{8}$$