Explanation: A positive temperature coefficient (PTC) describes how a material's electrical resistance changes with temperature. For materials with a PTC, an increase in temperature causes their resistance to rise. Conversely, if the temperature of such a material decreases, its resistance will also decrease. Therefore: * **A) Resistance increases as the temperature increases** directly states the definition of a positive temperature coefficient. * **B) Resistance decreases as the temperature decreases** describes the inverse relationship, which is a natural consequence of having a positive temperature coefficient. If resistance goes up with temperature, it must go down when temperature goes down. Both statements accurately reflect the behavior of a material with a positive temperature coefficient, making C the correct answer. This characteristic is important in electronics, affecting component performance and design, particularly in circuits sensitive to temperature variations.