All of the bonds on a certain exchange are designated by a
3-letter, a 4-letter, or a 5-letter code that is created by using the
26 letters of the alphabet. Which of the following gives the
maximum number of di¤erent bonds that can be designated
with these codes?


26(26^3 + 26^4)
(B) 26(26^3 + 26^5)
(C) 27(26^3 + 26^5)
(D) 27(26^3) + 26^5
(E) 26^3 + 27(26^5)


Please advice