Two plane wave fronts of light are incident on a thin convex lens and on the refracting face of a thin prism. After refraction at them the emergent wave fronts respectively become
(a) plane wave front and plane wave front
(b) plane wave front and spherical wave front
(c) spherical wave front and plane wave front
(d) spherical wave front and spherical wave front
(e) elliptical wave front and spherical wave front