The dance crew, after performing for the crowd, wash the paint from their faces.

which subject-verb agreement rule applies to this sentence?

use a singular verb with a singular subject
use a plural verb with a plural subject
use a plural verb with a collective subject functioning as individual parts
use a singular verb with a collective subject functioning as a unit

I believe the best option to be the third one: use a plural verb with a collective subject functioning as individual parts.

Explanation:

The subject of the sentence we are studying here is "the dance crew". The word "crew" is singular and, because of that, we would expect the verb to conjugated in the singular form as well - "washes". However, since "crew" is a collective noun - it indicates a collection or a number of things or people -, there are two possible ways to conjugate verbs with it. If we think of crew as a unit, the verb shall be singular. But, if we think of it as the individuals who are part of, each one of them performing an action, then the verb shall be in the plural form.

In conclusion, if the verb is in its plural form - "wash" -, the best explanation for its subject-verb agreement is the third option:

use a plural verb with a collective subject functioning as individual parts

the excerpt from chapter 2 of "animal farm", by george orwell that is an example of foreshadowing is "these three (snowball, napoleon, and squealer) had elaborated old major's teachings into a complete system of thought to which they gave the name of animalism." animal farm is an allegory of how czarist russia developed into communist russia with all its corruption. old major's teachings represent marx's theories turned into communism, animalism, by the three pigs. this foreshadows the oppression and corruption that will follow this revolt.