SAT Question 20ea68b7: Form Structure And Sense answer and explanation

English - Form Structure And Sense - Plural And Possessive Nouns
0:00
FREE OFFICIAL BANK
It can take time for proposed amendments to the US Constitution to become law. For example, the Twenty-Second Amendment, which limits the number of ______ can serve, was first proposed in 1947 but wasn’t approved by the required three-fourths majority of state legislatures until 1951.
26
Difficulty:Medium
Which choice completes the text so that it conforms to the conventions of Standard English?