If temperature is increased, the temperature coefficient of a metal

ANS:B - decreases

The answer is B.

Metals are ~indeed~ positive temperature coefficient, but the magnitude of that positive value decreases as temperature increases as given by α = 1/(T+To), or since at 0°, αo = 1/To; then it follows that αc = 1/(T+(1/αo)). In fact, for any material, the temperature coefficient is maximum at 0°.