A particle starts from the origin of coordinates at time t = 0 and moves in the xy plane with a constant acceleration `alpha` in the y-direction. Its equation of motion is `y= betax^2`. Its velocity component in the x-direction is
A. variable
B. `sqrt(((2a)/(b)))`
C. `(a)/(2b)`
D. `sqrt(((a)/(2b)))`