Hi, Can you help me find out how to aprouch this question?

All of the stocks on the over-the-counter market are designated by either a 4-letter or a 5-letter code that is created by using the 26 letters of the alphabet. Which of the following gives you the maximum number of different stocks that can be designated with these codes?

a) 2(26^5)


b) 26(26^4)


c) 27(26^4)


d) 26(26^5)


e) 27(26^5)

How should I approuch this problem?

I would think that because the there are 5 convination letters, each one of them with 26 letters of the alphabet. the answer is "B", However this is not true.

Thanks!