Which of these functions describes a wave moving in x direction?

Which of these functions describes a wave moving in −x direction? (i) y = A cos(kx − ωt) + B sin(kx − ωt). (ii) y = A cos(kx − ωt) + B cos kx + ωt + π 4 . (iii) y = A cos kx + ωt + 3π 8 + B sin kx + ωt − 5π 8 . (iv) y = A cos kx − ωt + π 4 + B sin kx + ωt − 3π 8 . (v) y = A sin(kx − ωt) + B sin(kx + ωt).