The given pair VERBAL : WRITTEN represents an antonym relationship — verbal (spoken) is the opposite of written.
We need a pair which is NOT an antonym relationship (because the question wants an opposite pair).
Day : Night → antonyms (opposites in time)
King : Queen → not antonyms, but a gender-based pair (both are royalty)
Monastery : Temple → not antonyms, both are places of worship -> best answer.
Long : Short → antonyms (opposites in measurement)