In right triangles we use SOH CAH TOA to help find missing angles and sides.
The first tells us secant is opposite over adjacent. That is tangent, so NO
The second is NO as well, since they give us cotangent. Second is NO.
The third is coseceant, which is again opposite over adjacent. Third is NO.
We got three NOs so the last one must be right. And it is: secant is hypotenuse divided by adjacent. Since secant is 1 divided by the cosine, that matches up to soh CAH toa, the CAH part.
Thus, D is the best choice.
