When the present participle of a verb is used in conjunction with a verb the verb is referred to. 1,progressive,2futuristic,3infiniti ve,4irregular

This is called the progressive verb form. Most commonly known are the present and the past progressive, known also as present and past continuous forms of a verb. And example would be saying that someone "is working", or "was working", where we use the participle working and helping verb "is", that is, "was".

The answer for the question is progressive verb. Progressive verbs are verb tense used to show an ongoing action in progress at some point in time. we can have present progressive verb (singing), future progressive ( will be singing). Infinitive verbs are verbs that do not show tense, numbers, mood, and person. An irregular verb is a verb in which the past tense is not formed by adding the usual -ed ending. Examples include; sing (past tense sang), feel (felt).

The answer is of course c