Match List I with List II:

List I (Transducer)		List II (Application)
(A)	Pirani gauge	(I)	Liquid level
(B)	Dielectric gage	(II)	Displacement
(C)	Magnetostriction gage	(III)	Gas flow
(D)	Variable capacitance pressure gage	(IV)	Sound

Choose the correct answer from the options given below:

1.) Pirani gauge

Pirani Gauge is a pressure transducer.

The Pirani gauge measures the vacuum pressure-dependent thermal conductivity from the heated wire to the surrounding gas. 

2.) Dielectric gauge

These are also known as the capacitive transducer.

Capacitive Transducer is mostly used for the measurement of liquid level.

In a dielectric gauge, a change in capacitance due to a change in the dielectric is known by its corresponding liquid level or thickness.

3.) Magnetostriction gauge

A magnetostriction transducer is a device that is used to convert mechanical energy into magnetic energy and vice versa. 

A magnetostriction gauge is used for the production of ultrasonic sound.

4.) Variable capacitance pressure gauge

A linear change in capacitance with changes in the physical position of the moving element is detected by a variable capacitance pressure gauge.

Hence, the correct answer is option 4.