Question

The most common linking verbs are (1 point)

auxillary verbs.
intransitive verbs.
various forms of be.

Answer 1

C.) Various forms to be: am, is, are, was, were, being, been

Answer 2

A linking verb connects two parts of a sentence. Auxiliary verbs are used to create complex tenses, such as future perfect continuous (will have been going - where will have been are all auxiliary verbs). Intransitive verbs are intransitive - they are not linking.
So, having this in mind, the most common linking verbs are various forms of be.
For example:
She is very tall.