Which of the following is the past participle of the verb "begin"?

The past participle of the verb "begin" is "begun." In English, verbs can take different forms: the base form (begin), the past simple form (began), and the past participle form (begun). The past participle is typically used in perfect tenses, such as in the present perfect ("I have begun my work") or the past perfect ("I had begun my work").

In contrast, "began" is the simple past tense form used to describe actions that happened in the past but does not indicate completion in the same way the past participle does. The phrase "to begin" is the infinitive form and does not indicate any tense. "Will begin" is a future construction and also does not indicate the past tense or perfect aspect. Thus, "begun" is specifically the form that correctly represents the past participle of the verb "begin."