A.
The area of the largest square is 285 square units, because it is the sum of the area of the square with the longest side, 225 square units, and the area of the triangle formed by the squares, 60 square units.
B.
The area of the largest square is 124 square units, because it is the sum of the area of the square with the shortest side, 64 square units, and the area of the triangle formed by the squares, 60 square units.
C.
The area of the largest square is 289 square units, because it is the sum of areas of the two smaller squares, 64 square units and 225 square units.
D.
The area of the largest square is 349 square units, because it is the sum of areas of the two smaller squares, 64 square units and 225 square units, and the area of the triangle formed by the squares, 60 square units.