Step 1: Define the word "Fervour."
"Fervour" means intense and sincere enthusiasm or emotion. Its associated with warmth, zeal, and devotion.
Step 2: Analyze the given options:
(1) Ardor: Intense enthusiasm and passion — same as fervour.
(2) Zeal: Eager desire or fervent devotion — similar in meaning.
(3) Passion: Strong emotional feeling — again, similar to fervour.
(4) Apathy: Lack of interest, enthusiasm, or concern — the exact opposite.
Hence, the correct antonym is (4) Apathy.