d. Infinitive
Verbal phrases are phrases consisting of a verb, and modifiers, objects or objects, that do not act as verbs in a sentence but as a noun, an adjective or an adverb. Infinitive phrases start with a verb in their infinitive form (to + base form of the verb) and are followed by any objects, and/or modifiers.
The verbal phrase "To travel around the world" has the characteristic of an Infinitive phrase, and it acts as a noun and the subject of the sentence, as it is the idea or action that is being discussed in it.
