here, you could approach this question with a sort of critical reasoning.

This way, you stretch your mental muscles and pick the right answer using your flexibility. That is this test is all about.

To confirm the survey, or for being valid, a survey must compare similar things or clusters. As such, we must have homogeneous plots.

D is the best. provincial is not the most logic answer here

Regards

Blank is before the comparison..................than in mixed communities ............Homogeneous ........similar

thus D is the best.

The word next to the blank is "neighborhoods". Provincial neighborhoods does not make sense in the context.
And since we need to find the opposite of "mixed communities", homogeneous neighborhoods seems like a more probable answer here.
Hope it helps!