1) What is tan(a) for the triangle shown?

BC has a length of 8.
BA has a length of 17.
AC has a length of 15.
The right angle is on the BC sides lower left hand corner.

A) 8/15
B) 15/8
C)17/8
D) 8/17

Whenever I try this I get weird answers. I am extremely confused and help would mean so much right now. Thank you!

tangent is 8/15 I am assuming C is the right angle.