The correct answer is: D. Barometer
A barometer is an instrument used to measure atmospheric pressure. It is a simple device that consists of a glass tube filled with mercury and an inverted cup. The mercury in the tube rises and falls in response to changes in atmospheric pressure. The height of the mercury column can be used to measure the pressure.
A barkometer is a device used to measure the bark thickness of trees. It is a non-destructive device
that uses ultrasonic waves to measure the thickness of the bark.A bolometer is a device used to measure infrared radiation. It is a sensitive detector that converts infrared radiation into heat.
A spectrometer is a device used to measure the spectrum of electromagnetic radiation. It is a complex instrument that can be used to measure the wavelength, intensity, and polarization of electromagnetic radiation.