4) A
Radius of largest circle = 4d ÷ 2 = 2dArea of largest circle = π (2d)² = π 4d²
Radius of third largest circle = 3d ÷ 2 = 1½d
Area of third largest circle = π (1½ d)² = π 2¼d²
Radius of second largest circle = 2d ÷ 2 = 1d = d
Area of second largest circle = π (d)² = π d²
Radius of smallest circle = d ÷ 2 = ½d
Area of smallest circle = π (½d)² = π ¼d²
Area of the larger shaded area = π 4d² – π 2¼d² = πd² (4 – 2¼) = π 1¾ d²
Area of the smaller shaded area = π d² – π ¼d² = πd² (1 – ¼) = π ¾ d²
Total shaded area = π 1¾ d² + π ¾ d² = πd² (1¾ + ¾) = πd² 2½ = ⁵⁄₂ πd² (2½ = ⁵⁄₂)
