Answer: Graph 1
Explanation:
When theta/ the angle is 0, the y value is also 0. Since sin = y/r --> 0/r = 0.
Therefore, the graph of sine will pass through (0,0), which graph one does.
Also, the y value is 0 again when the angle is pi. sin = y/r --> 0/r = 0, thus passing through the point (pi,0)
This will make more sense if you know what a unit circle is.