函数z=arcsin[(x2+y2)/4]+ln(x2+y2)的定义域是()

函数z=arcsin[(x2+y2)/4]+ln(x2+y2)的定义域是()
A、{(x，y)∣0≤x2+y2≤4}
B、{(x，y)∣0≤x2+y2﹤4}
C、{(x，y)∣0﹤x2+y2≤4}
D、{(x，y)∣0﹤x2+y2﹤4}
【正确答案】：C