An electric current is expressed by a unit called ___________.

Correct option is B

An electric current is expressed by a unit called an ampere. It is named after the French physicist Andre-Marie Ampere, who is known for his contributions to the study of electromagnetism. The Ampere is one of the seven base units of the International System of Units (SI), which is the modern form of the metric system.
 The meter is the base unit of length.
 Watt is the standard unit of Power.
 Joule is the standard unit of Energy.