The correct answer is (C). The formula to find the area of a square is Side × Side. If each square has an area of 25, then each side of the square must be 5 (because 5 × 5 = 25). So the dimensions of the rectangle are 5 × 10. The perimeter is the sum of all the sides, and is therefore 5 + 10 + 5 + 10 = 30.