A. 675 units²
The formula for the surface area of a square pyramid is ...
A = s(s +2h)
where s is the side length of the base, and h is the slant height of a face.
use the formula
The given pyramid has s=15 and h=15, so the surface area is ...
A = (15)(15 +2×15) = 15(45) = 675 . . . square units