Please help!?

Question

The displacement of a string carrying a traveling sinusoidal wave is given by y(x,t) = A sin (kx-wt-)φ. At time t=0 the point at x=0 has a displacement of 0 and is moving in the +y direction. The phase constant φ may take the value:
a. 180 deg. b. 90 deg.

Answer 1

...and the equation is y(x,t) = A sin(kx-wt-φ). I hope?

Since the displacement = 0 (or y(0,0)=0)
the phase φ=180 deg

the answer is (a)