Hello!
We want to find the length of the side adjacent to our 54 degree angle. As we are given the opposite side, let's find the tangent.
tan54≈1.38
This gives us the equation below.
1.38=16/x
1.38x=16
x≈11.59
Our answer is very close to B. The thing is, we solved our equation using the rounded tangent. Going with the whole number would give us the exact answer.
Therefore, our answer is B) 11.62
I hope this helps!