Answer: second option.
Step-by-step explanation:
You must apply [tex]sin\alpha=\frac{opposite}{hypotenuse}[/tex]
Then, given the right triangle and the angle D, the opposite side and the hypotenuse of the triangle are the following:
[tex]opposite=20\\hypotenuse=25[/tex]
Therefore, when you substitute values, you have:
[tex]sinD=\frac{20}{25}[/tex]
Reduce the fraction, then you obtain:
[tex]sinD=\frac{4}{5}[/tex]
