Mａｔｈ probability

いちろーです。
たびたびすみませんが下記問題おしえてください。

A groupe of 10 people includes one married couple. If 4 people are selected at random, what is the probability that the married couple is selected?

(A) 1/90
(B) 1/45
(C) 1/35
(D) 2/15
(E) 4/15

正解はＤです。