Which term denotes 'A significant or memorable day'?

• A. Red Letter Day
• B. Wise People
• C. Negative Prefixes
• D. Concrete Examples

Answer: (A)

Think about how language uses colorful phrases to capture memorable events. A red-letter day is an idiom for a day that stands out because it’s especially important, happy, or noteworthy. The origin lies in old calendars where important religious or public days were printed in red ink to make them pop from the ordinary days. That visual cue—red ink marking something special—became a metaphor for any day that feels significant. That’s why this term is the best fit for “A significant or memorable day.” The other options aren’t about days at all: wise people refers to individuals, negative prefixes are about negating meaning in words, and concrete examples describe specific instances used for illustration, not a memorable day.