Disney World was the fun of all the theme parks that I've visited.

What is the best way to rewrite this sentence?
A.
Disney World was the most fun of all the theme parks that I've visited.
B.
Disney World was the funner of all the theme parks that I've visited.
C.
Disney World was the funnest of all the theme parks that I've visited.
D.
Disney World was the more fun of all the theme parks that I've visited.