Answer:
In this case, D
Explanation:
Sin(30+60)=0.8939966636 which can be rounded to 0.89.
Now that we got that out of the way, we supposedly can follow the process of elimination.
It's clearly not A since we know the answer isn't equivalent to zero.
1/2 equals 0.5, meaning B's also not it.
We also know the answer isn't D, since 0.89 does not equal 1.
That only leaves C. Yet when check, just in case, √3/2 equals 1.22474487, meaning that's not the answer.
We've eliminated every answer so far, meaning we should go back and check our work. As I stated earlier, 0.8939966636 can be rounded to 0.89, but it can also be rounded to 1. Meaning, the closest answer to what we're looking for is D.
Of course, there could always be an error in the question itself, but unfortunately, there's no way to confirm that without asking your instructor or tutor.
I hope that helps.