*$_For small temperature difference, the heat transfer rate as per Newton's law of cooling is proportional to (where, Δt = excess temperature)?

• A. ≈í√Æt
• B. ≈í√Æt¬¨‚â§
• C. ≈í√Æt¬¨‚â•
• D. ‚Äö√ √∂≈í√Æt