E7G12

What is an operational amplifier?

1. AA high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
2. BA digital audio amplifier whose characteristics are determined by components external to the amplifier
3. CAn amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
4. DA RF amplifier used in the UHF and microwave regions

Pick an answer to check it.