The fact that they have been awarded so many prizes _______, even more, their many years of hard work for the local community.
Which of the following options CORRECTLY completes the sentence above?

A subject must agree with its verb in number. The subject in this sentence (the fact that…) is singular, so we need a singular verb (highlights).
The other options are incorrect.
- "Have highlighted" is in the past perfect tense, which is not appropriate for this sentence. The sentence is about the present situation, so the present tense is used.
- "Highlight" is the singular form of the verb, but the subject of the sentence is plural ("they").
- "Highlighting" is the gerund form of the verb, which is used to describe an action that is happening at the same time as something else. In this sentence, the action of highlighting is not happening at the same time as the action of being awarded prizes.