ANSWER :
(A) AT RIGHT ANGLES TO THE DIRECTION THE WAVE TRAVELS.
EXPLANATION :
TRANSVERSE WAVES IS THAT IN WHICH THE PARTICLES VIBRATE WITH AN UP-AND-DOWN MOTION. THE PARTICLES IN A TRANSVERSE WAVE MOVE ACROSS OR PERPENDICULAR TO THE DIRECTION THAT THE WAVE IS TRAVELING OR AT RIGHT ANGLES TO THE DIRECTION THE WAVE TRAVELS.