Explanation: The task at hand is to correct the sentence "K. Viswanadh is one of the best director in Andhra Pradesh." The primary issue with the original sentence is the use of the singular form "director" when referring to multiple directors. The phrase "one of the best" inherently implies that there are multiple directors being compared, and thus, the noun "director" should be in its plural form, "directors."
In English grammar, subject-verb agreement is a fundamental rule that ensures the subject and verb in a sentence agree in number (singular or plural). When the subject is singular, the verb should also be singular, and when the subject is plural, the verb should be plural. However, in this case, the issue is not with the subject-verb agreement but with the use of the correct form of the noun.
The correct sentence should be "Viswanadh is one of the best directors in Andhra Pradesh." This correction addresses the grammatical error by using the plural form "directors," which is appropriate when referring to multiple directors. The sentence structure is clear and maintains the original meaning that Viswanadh is among the best directors in Andhra Pradesh.
It is important to note that the preposition "in" is used correctly in this context, as it indicates the location or region where Viswanadh is considered one of the best directors. The preposition "of" would be incorrect in this context, as it would imply possession or a part-whole relationship, which is not the intended meaning.
In summary, the correct answer is (D) "Viswanadh is one of the best directors in Andhra Pradesh." This option correctly uses the plural form "directors" and maintains the original meaning of the sentence. Understanding and applying the rules of subject-verb agreement and proper use of singular and plural forms is crucial for constructing grammatically correct sentences.