The resistance of a copper conductor at 20°C is 10 Ω and RTC is 0.0039 per °C. Find the temperature coefficient of resistance (RTC) at 0°C.

• A. 0.000124 per °C
• B. 0.0000423 per °C
• C. 0.00423 per °C
• D. 0.00324 per °C