Final answer:
The verb phrase in the supplied sentence is 'may be preserving', and it's essential to recognize the structure and function of verb phrases when analyzing sentences. Prepositional phrases are never subjects, and verb structures like gerunds and infinitives can function differently within sentences.
Step-by-step explanation:
The verb phrase in the sentence given is 'may be preserving'. This phrase encompasses a modal verb ('may'), an auxiliary verb ('be'), and the main verb ('preserving'). The task involves not just identifying verbs but also understanding their forms and functions within sentences. For example, in sentence options b, c, and d, the verb phrases are 'was walking', 'is preparing', and 'have been studying' respectively, each consisting of auxiliary or modal verbs combined with main verbs.
When reviewing subject/verb agreement, it is crucial to consider the actual subject of the sentence, as demonstrated in the explanation with the play and its verb 'comes'. Prepositional phrases, such as 'with such true witticisms and parables', do not act as the subject. Participles, gerunds, and infinitives can function in several ways within sentences, such as adverbials or adjectives, and identifying these can be a step in understanding complex sentences.