Consider the planar surface $z=0$ below, which is lit with a directional light source $I=(-1,0,-1,0).$ Which of the following is the point on this surface, at which the specular component of the

reflection is maximum with respect to the viewer that is located at point $p=(1,0,1,1)?$

$(1,0,0,1)$

$(2,2,0,1)$

$(0,1,0,1)$

$(1,0\mathrm{.}5,0,1)$

$(2,0,0,1)$

$(1,1,0,1)$

$(0,2,0,1)$

$(0\mathrm{.}5,1,0,1)$