Concept:A thermistor is a semiconductor device whose electrical resistance varies greatly with temperature.
Explanation:A heat sensitive resistor changes its resistance in response to heat.
Thermistors are made from metal oxide semiconductor materials.
They are commonly used for accurate temperature measurement in circuits.
The other options do not fit the description.
A thermometer is an instrument for measuring temperature, but it is not a semiconductor resistor.
A thermostat is a switch used to regulate temperature.
A thermopile consists of thermocouples that convert heat energy into electrical energy.
Therefore, the heat sensitive resistor made from a semiconductor is called a thermistor.
Answer:C. thermistor