The correct option is B Pyrometer
An instrument used to measure high temperature is Pyrometer.
A pyrometer is used to measure high temperatures in the furnace. It is a type of remote sensing thermometer used to measure temperature for the surface.
Pyrheliometers measure only the sunlight from a small area around the sun.
A tachometer is an instrument measuring the rotation speed of a shaft or disk.
A gas pycnometer is a laboratory device used for measuring the density or, more accurately, the volume of solids.