The teenagers went to town to muse over whether going to college or to university was the better choice. which part of the sentence is an infinitive? to townto museto collegeto university

Although it is usually relatively easy to spot an infinitive because of its form (the word TO + verb), sometimes you may be led to believe that any combination of TO and a word is an infinitive, which is not true - the word following TO has to be a verb. This is why to town, to college, to university are incorrect answers, because all of those words are nouns.

The correct answer is to muse.