With some simple rearrangement, we can rewrite the numerator as

Then factorizing the difference of squares,
, we end up with

I would go with A but I am not 100% sure so you may want to check however you can.
15/100 × 215 = 3225/100
= 32.25
i am a mathematics teacher. if anything to ask please pm me
Parameterize the part of the sphere by

with

and

. Then

So the area of

(the part of the sphere above the cone) is given by