单项选择题
Life expectancy among adults 45 and 65 years
of age by family income, sex, and race: United States, average annual
1979-89
In the figure above, the diameter of the circle is 20 and the area of the shaded region is 80π. What is the value of a + b + c + d
A． 144
B． 216
C． 240
D． 270
E． 288
B． 216
C． 240
D． 270
E． 288