Hi there!
Let's first have a look at the basic goniometric statements, which say the following:
[tex] \sin( \alpha ) = \frac{opposite \: side}{hypotenuse} \\ \cos( \alpha ) = \frac{adjecent \: side}{hyptenuse} [/tex]
When we're looking from the point of view of angle G, we have the following data:
- The length of the opposite side is 15
- The length of the adjecent side is 8
- The length of the hypotenuse is 17
Now plug in this data into our general formulae.
[tex] \sin(g) = \frac{15}{17} \\ \cos(g) = \frac{8}{17} [/tex]
Hence, answer B. is correct.
~ Hope this helps you!