A) Computable Enumerable Languages
I'm guessing Computable Enumerable Languages are Recursively Enumerable Languages.
(I'm answering this according to a closure properties table given by Ravindrababu Ravula sir. Below is an explanation that I could find when I googled the same.)
The Turing-recognizable (or recursively enumerable) languages are closed over homomorphism.
Consider the case where L is RE. Design a NTM M for H(L), as follows. Suppose w is the input to M. On a second tape, M guesses some string x over the alphabet of L, checks that H(x) = w, and simulates the TM for L on x, if so. If x is accepted, then M accepts w. We conclude that the RE languages are closed under homomorphism.
Source: University of Alabama Assignment
Please correct me if I'm wrong.