we know that
[surface area for a rectangular prism with a square base ]=2*s²+4*s*h
2*s²----> Is the surface area of the bases
4*s*h---> is the lateral area
s=2 units
h=4 units
[surface area for a rectangular prism with a square base ]=2*2²+4*2*4
surface area=8+32----> 40 units²
the answer is
40 units²