Q. What is the meaning of the word ‘ephemeral’?

Explanation:

Ephemeral means lasting for a very short time; transitory or short‑lived (synonyms: fleeting, transient, momentary). Etymology: from Greek ‘ephemeros’ meaning ‘lasting only a day’. Example: ephemeral trends or the short adult life of a mayfly.
Elimination of options:
– Option 1 (Permanent): Opposite of ephemeral.
– Option 2 (Mysterious): Relates to enigma, not duration.
– Option 4 (Loud): Pertains to sound, not time.
Hence, Option 3 (Temporary) is correct.