I think it’s b
I hope I’m right
Use the Pythagorean Theorem:
A²+B²=C²
6²+5²=C²
36+25=C²
61=C²
√61=C
So the answer is C.
Last time I checked that was about right, but it's been a few years since then.
You're answer is going to be C
325.81
Hope this helps