Which base unit, discovered in 1820, represents one coulomb of electric current per second?

Ampere

The correct answer is option 4. Ampere.

The unit "Ampere" (symbol: A) is used to measure electric current. It is named after the French physicist André-Marie Ampère, who made significant contributions to the understanding of electromagnetism.

One ampere is defined as the amount of electric current that flows through a conductor when a charge of one coulomb passes through it per second. Essentially, it measures the rate of flow of electric charge in a circuit.

This unit is fundamental in understanding and quantifying the flow of electricity in various electrical devices, circuits, and systems.