Question

A particle is moving along a straight line parallel to the x axis at a distance 'd' away from it. It moves with a constant velocity 'u'. At a point (x,d)what is the velocity along r̂ ?
1.uy /(x^2+y^2)^0.5
2.u
3.ux/y
4.ux/(x^2+y^2)^0.5