Option 1 -> Quick is a synonym of prompt, not an antonym.
Option 2 -> Delayed means postponed or late, which is the opposite of prompt.
Option 3 -> Short refers to length or duration, unrelated to the concept of promptness.
Option 4 -> Immediate is a synonym of prompt, not an antonym.
Hence, Option 2: Delayed -> "Prompt" means done without delay or immediately, while "delayed" means postponed or occurring later than expected, making them perfect antonyms -> correct