Analysis of gender differences in life expectancies of Americans shows that :

a) the life expectancy of black males is higher than that of black females 

b) females have longer life expectancies than males at every age, regardless of race and ethnicity 

c) females are more likely to live to be in their 80s, but males are more likely to live to be centenarians (100 or above) 

d) males have longer life expectancies than females at every age, regardless of race and ethnicity