Which term best describes the underlined words?

The best way to save money is not to spend any of it.

A.

gerund phrase

B.

participial phrase

C.

infinitive phrase

Question Resources

Nothing is underlined, but I assume that the underlined words would be either "to save" or " (not) to spend" or both. In any case, the correct answer would be C - infinitive phrase, because these verbs are in their infinitive form. "Gerund" and "participle" would end in - ing,