I think "254 h" is 254th.

So the question could be what is the 254th term?

ABCDEABCDEABCDEABCDEAB....

We see that ABCDE is just repeated on and on.

In ABCDE, the 5th term is E

In ABCDEABCDE, the 10th term is E

In ABCDEABCDEABCDE, the 15th term is E

etc....

That means the E is repeated every 5th term:

5th, 10th, 15th, ....195th, 200th, 205th, .....245th, 250th, 255th, oopps...

Zeez, if the 255th term is E, then the 254th term must be D.