Institution: জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় (JKKNIU) Exam: ক ইউনিট || জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় || 2012
Topic: Correction (Sentence Correction), Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The correct choice among the options provided is D) "He said," because it adheres to standard grammatical conventions for reported speech in English.

When reporting what someone has said, it is common practice to use a comma before the following dialogue or a quote. The phrase "He said," effectively introduces a statement or a quotation that would follow. The comma is crucial in this context, as it signals that what follows is distinct from the reporting verb.

Examining the other options reveals their shortcomings:

- A) "He requested me,," contains unnecessary and incorrect punctuation, which disrupts the flow and clarity of the sentence.
- B) "He asked,," similarly includes a double comma, which makes it grammatically incorrect and confusing.
- C) "He said,," while almost correct, lacks a following quote or statement to provide context and coherence.

Thus, choice D is the best option as it punctuates appropriately while adhering to grammatical norms, which enhances clarity and readability in written communication.