Topic: Article,

Best Answer Explained in Below-:

In the sentence "He is __ most famous teacher of this college," the most suitable article to fill in the blank is "the," making the correct phrase "He is the most famous teacher of this college."

The use of "the" indicates that we are referring to a specific teacher within the context of that college. "The" is a definite article, which means it highlights a unique or specific noun. In this case, "most famous teacher" suggests that among all the teachers at the college, he holds the highest recognition or distinction. Consequently, using "the" clarifies that there is a singular standout teacher rather than a general one.

In contrast, using "a" would imply that he is merely one of many famous teachers, which alters the intended meaning. "An" cannot be used here because it is only appropriate before words that begin with a vowel sound, which is not the case with "most." Therefore, "the" is the correct choice, signaling both specificity and an established understanding that he is the preeminent figure among the college’s educators.