Susan has selected exactly three crayons, each a different color, from a crayon box. How many crayon colors were represented in the box before her selection?

1. Exactly four distinct three-crayon color combinations were represented in the box before Susan selected three crayons.

2. Just before Susan`s selections, the box contained exactly five crayons.

这道题目答案是  c（both together）

four distinct three-crayon color combinations  是什么意思？

谢谢大家帮忙！