gre逻辑题第四套第七题为什么不选D?

gre逻辑题第四套第七题为什么不选D?
In Bassaria a group of that country's most senior judges has criticized the
uniform mandatory sentences recently introduced for certain specific crimes．The
judges argue that such sentences,by depriving them of all discretion in setting
sentences,make it impos-sible for them to consider either aggravating or
exten-uating circumstances and so make it impossible to achieve true justice―the
fitting of the severity of the punishment to the gravity of the particular
crime． 　　Which of the following,if
true,provides the strongest evidence for the claim that in Bassaria the newly
introduced mandatory sentences are not necessarily a change for the worse with
respect to achieving true justice as defined in the argument?
　　（A）Before mandatory
sentencing,judges in eastern Bassaria imposed strikingly different sentences
from those in western Bassaria for equally grave instances of the same kind of
offense．
　　（D）There used to be a wide
difference between the minimum and the maximum sentences allowed by law in cases
of crimes now subject to man-datory sentences．
对于A.D选项有疑问,