Question

Read the phrase.

Answer 1

Greetings!

The noun (buildings) is a possessive noun, meaning that it has a relationship of owning the other noun (windows). However, the possessive noun in this case is plural (ends with s) and is thus treated differently than a singular possessive noun: 

Singular: 
Building's Windows

Plural: 
Buildings' Windows 

In this scenario, since possessive noun end in s/is plural, we don't add the s.
The answer would therefore be the last option, "buildings' windows" 

Hope this helps!
-Benjamin

Answer 2

Answer:

The answer would be the last option, "buildings' windows"

Explanation:

Singular:

Building's Windows

Plural:

Buildings' Windows