You’re trying to find x which is the side opposite to the angle. You’re given the adjacent angle. To find the variable, you use tangent. So you plug in tan(x)= opposite/adjacent. In this case it would be tan(27)=x/15. Then you multiply both sides by 15 to be 15(tan(27))=x which is 7.6=x
I want to say A because 3 and 5 have 15 and 6:15 is sounds like a ratio and D is just 4/10