Answer:
'Offered'.
Step-by-step explanation:
A sentence comprises of several elements but verb is the one that inculcates action to the sentence.
Main verb is demonstrated as the verb that is associated with the subject of the sentence and functions to express the principle action, state of being, or connect the subject to the additional information about the subject given in the sentence.
In the given sentence, 'offered' is the main verb as it not only displays the principle action of the subject in the sentence but also functions to offer a 'lexical' meaning to it. Thus, 'offered' is the main verb.