Which underlined word should be corrected in this sentence for proper usage? Everyone of the convention's delegates voted.

The sentence “Everyone of the convention's delegates voted” contains an issue with the word "Everyone." In standard English, "everyone" is treated as a singular pronoun, which means it should correctly be followed by a singular verb. However, the structure here suggests that it is meant to imply unity among a group, which should ideally be expressed in a way that emphasizes this more effectively.

The correct phrasing would be to rephrase it to something like: “All of the convention's delegates voted” or simply keep "Everyone" and acknowledge that it should be “Everyone at the convention voted.” This highlights that all individuals participated while maintaining proper pronoun-verb agreement.

The other options do not present issues that require correction, as they maintain proper grammatical structures and fulfill standard usage rules, emphasizing clarity and correct pronoun usage.