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