Downzoning, zoning that typically results in the reduction of housing density, allows for more open space in areas where little water or services exist.

a) little water or services exist

b) little water or service exists

c) few services and little water exists

d) there is little water or services avaliable

e) there are few services and little avaliable water

问题：C选项如果把exists改成exist是不是就对了?D选项是不是把SERVICES改成SERVICE就对了？

期待大牛们的解答！