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)