I would say #1 and #4 are correct, #3 is wrong, and #2 is allowable and would should they were acting individually rather than as a group.
CMoS says:
5.8 Mass nouns A mass noun (sometimes called a noncount noun) is one that denotes something uncountable, either because it is abstract {cowardice} {evidence} or because it refers to an indeterminate aggregation of people or things {the faculty} {the bourgeoisie}; the latter type is also called a collective noun. As the subject of a sentence, a mass noun usually takes a singular verb {the litigation is varied}. But in a collective sense, it may take either a singular or a plural verb form {the ruling majority is unlikely to share power} {the majority are nonmembers}. A singular verb emphasizes the group; a plural verb emphasizes the individual members.
5.9 Mass noun followed by a prepositional phrase Mass nouns are sometimes followed by a prepositional phrase, such as
number of plus a plural noun. The article that precedes the mass noun signals whether the mass noun or the number of the noun in the
prepositional phrase controls the number of the verb. If a definite
article (the) precedes, the mass noun controls, and typically a
singular verb is used {the quantity of pizzas ordered this year has
increased}. If an indefinite article (a or an) precedes, then the
number of the noun in the prepositional phrase controls {a small
percentage of the test takers have failed the exam}