Two Sound Waves,one Wave Is Given by Y₁ = P_o $\omega$

Multiple Choice

Two sound waves,one wave is given by y₁ = p_o sin (kx - $\omega$ t) and the other by y₂ = p_o sin (kx - $\omega$ t + $\pi$ /4) .The phase constant resulting from the interference of the two waves is

A) $\pi$ /8
B) $\pi$ /4
C) $\pi$ /2
D) $\pi$
E) 0