I don't see it in the answers, but it seems to me that the correct answer should be:
"as much of AN art as"
but I think you can also say
" as much an art as"
I believe I usually would say "as much of an art as"... but now that I think about it, I'm not sure which one is most proper. I think dropping the "an" *might* be ok, but the first sounds more clear and correct:
"is as much of an art as".
Here are some more examples of proper English:
Swimming is "as good of AN exercise as" running.
Apples are "as good of a fruit as" oranges.
"This is as good as that."
B is "as good of an answer as" D
btw, how do you make these kind of comparisons in Mandarin Chinese?