The right adjective is belle.
The other options are all in masculine form.
C'est une belle dame.
(You get the conjugation by dropping the -ir from the infinitive and adding these endings)
A. Je: -is
B. Tu: -is
C. Il: -it
D. Elle: -it
E. On: -it
F. Nous: -issons
G. Vous: -issez
H. Ils: -issent
I. Elles: -issent
