这题怎么理解，取前5名，感觉只需要组合，不需要排列。1，2，3，4，5和1，3，4，2，5这其实最终呈现的不都是前5名吗

问题如下：

Gerd Sturm wants to sponsor a contest with a $1 million prize. The winner must pick the stocks that will be the top five performers next year among the 30 stocks in a well-known large-cap stock index. He asks you to estimate the chances that contestants can win the contest.

What are the chances of winning if the contestants must pick the five stocks in the correct order of their total return? If choosing five stocks randomly, a contestant’s chance of winning is one out of:

选项：

A.

142506

B.

17100720

C.

24300000

解释：