(A) Special occasion
(B) Important document
(C) Celebration
(D) None of these
🧠 Explanation:
The idiom “Red-letter day” refers to a day that is very special, important, or memorable. Historically, calendars marked important dates and festivals in red ink, distinguishing them from ordinary days. Over time, the phrase came to symbolize occasions of personal or public significance, such as celebrations, achievements, or landmark events. Understanding idioms like this is essential for exams like PPSC, as they test both language comprehension and general knowledge. Recognizing the meaning and usage of idiomatic expressions helps in writing, speaking, and answering verbal reasoning questions effectively.