Answer:
D) Cos X = Sin Y
Step-by-step explanation:
If angle X and Y are complementary angles, as shown in the attachment, then;
[tex]\cos X=\frac{a}{b}[/tex]
and
[tex]\sin Y=\frac{a}{b}[/tex]
We can see clearly that both ratios are the same.
This implies that:
[tex]\cos X=\sin Y[/tex]
Therefore the correct answer from the given options is D