设 $f(x, y)$ 是连续函数,则 $\int_{\frac{\pi}{6}}^{\frac{\pi}{2}} \mathrm{~d} x \int_{\sin x}^1 f(x, y) \mathrm{d} y=(\quad)$
A. $\int_{\frac{1}{2}}^1 \mathrm{~d} y \int_{\frac{\pi}{6}}^{\arcsin y} f(x, y) \mathrm{d} x$
B. $\int_{\frac{1}{2}}^1 \mathrm{~d} y \int_{\arcsin y}^{\frac{\pi}{2}} f(x, y) \mathrm{d} x$
C. $\int_0^{\frac{1}{2}} \mathrm{~d} y \int_{\frac{\pi}{6}}^{\arcsin y} f(x, y) \mathrm{d} x$
D. $\int_0^{\frac{1}{2}} \mathrm{~d} y \int_{\arcsin y}^{\frac{\pi}{2}} f(x, y) \mathrm{d} x$