The subdivisions filled with “McMansions” created at the end of the 20th century represent the prosperity of the era because:
A.
houses were larger than in other eras.
B.
all the houses resembled each other.
C.
they featured very similar interior layouts.
D.
all of the above

The correct option of the given question is (D) All of the above.

Explanation:

McMansions are houses that are fairly large in size. These were built with low-quality materials depending on an individual's taste or wealth. Their size and certain physical features distinguished them from other buildings in that area.  

In the 1980s and 1990s, these mansions became quite famous. Everyone in that era desired to have such houses. These were built in such a way that the house looked very expensive than usual.

the answer is b. i'm positive it's that answer.