Answer:
you can split the garden in: 1/2 circles x 4 (because you have 4 half-circles) + a square.
the square's area is 4 x 4 = 16; the circles is pi x R x R (pi = aprox 3.14, R of the cirlce is 4m / 2 = 2m, because the square's side is 4m and is the same size with circle diagonale: Diag of circle = 2 X Radius => Radius = Diag / 2)
than answer will be: 16 + 3.14 x 2 x 2 x 2 (the last 2 is, because you have 4 halves of circles, than you will have 2 full circles) = 45.12, than answer is H, because 41 is the nearest number to 45.12