A

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

B

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

C

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

D

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