A

$\displaystyle\int_0^1dy\int_{\sqrt y}^{2-y}f(x,y)dx$

B

$\displaystyle\int_0^2dy\int_{y^2}^{2-y}f(x,y)dx$

C

$\displaystyle\int_0^1dy\int_0^2f(x,y)dx$

D

$\displaystyle\int_0^1dy\int_{y^2}^{2-y}f(x,y)dx$