Diagram a is s orbital, b is p orbital and c is d orbital.
a) The first diagram represents an s orbital. The s orbital is spherical and symmetrical, centered on the nucleus. The 1s orbital is the closest to the nucleus and it’s found in the n=1 shell.
b) The second diagram represents a p orbital. The p orbital is found in the n=2 shell and above. The specific p orbital in the diagram could be either the px or the py orbital, as they both have similar shapes.
c) The third diagram represents a d orbital. The d orbital is found in the n=3 shell and above. The specific d orbital in the diagram could be either the dxy, dyz, or dxz orbital, as they all have similar shapes.