Final answer:
The correct MLA citation for the student's personal letter is (a) "Ivan, Marty, Letter to the author, 4 Feb. 2021." following MLA guidelines for citing personal letters.
Step-by-step explanation:
The correct punctuation for a works-cited entry for a personal letter should follow established guidelines, like those of the Modern Language Association (MLA). Starting with the author's last name, followed by a comma, then the author's first name, we conclude with a period. Next, the title of the letter follows, treated as a source. Since this is a personal letter, the title is not italicized or enclosed in quotation marks; it is simply capitalized and followed by a period. Finally, the date of the letter is listed, following the form of day, abbreviate month, and year, and ends with a period.
Considering the given options and the MLA style guidelines, the correct entry would be:
Option a: Ivan, Marty, Letter to the author, 4 Feb. 2021.