a grammar question

[curious]

Which do you think is right?

The singing of Mr. Casanova was ---- elegant ---- to overshadow, somewhat, the nominally top-billed star of the evening, Aprile Millo.

A) more / than
B) as / as
C) so / as
D) so / that
E) not / too

[Tdol]

c

[curious]

What would as...as mean in this sentence and why would it be wrong? Would it not mean "...elegant enough to overshadow...."?

[Tdol]

With the infinitive, we use 'so...as to'.