E7B19 (B) 
What is a parametric amplifier?
A. A type of bipolar operational amplifier with excellent linearity derived from use of very high voltage on the collector
B. A low-noise VHF or UHF amplifier relying on varying reactance for amplification
C. A high power amplifier for HF application utilizing the Miller effect to increase gain
D. An audio push-pull amplifier using silicon carbide transistors for extremely low noise 
