Question

Which part of the sentence is an infinitive?

Answer 1

An infinitive is a verb not attached to a particular object or tense
so yes it is B

Answer 2

Answer:

 The correct answer is option b) to muse.

Explanation:

The basic form of a verb is called an infinitive. This verb is usually called "present infinitive", which is the most widely used. Although it is not the only one since there are four other verb forms composed with infinitives in English: perfect infinitive, perfect continuous infinitive, continuous infinitive and passive infinitive.

The existing forms of the infinitive are:

infinitive with to = to + root of the verb

infinitive without to or "zero infinitive" = root

This root of the "present infinitive" is the verb form that is in the dictionaries.