For
the first time in the modern era, non-Hispanic Whites are officially a minority
in California,
which amounts to a little less than half the population of the state, down
from nearly three-quarters only a decade ago
A.which amounts to a little less than half the population of the state, down from
nearly three-quarters only a decade ago
B.which amounts to a little less than half the population of the state, down from
a decade ago, when it was nearly three-quarters
C.and that amounts to a little less than half the population of the state, down
from a decade ago, when they were nearly three-quarters
D.amounting to a little less than half the population of the state, down from
nearly three-quarters a decade ago
E.amounting to a little less than half the population of the state, down from
what it was a decade ago by nearly three-quarters
请牛人解释一下各个选项，为什么是d啊。谢谢 | 
