Final answer:
d. Clamp-on. Ammeters are used to measure the rate of flow of electric current in a circuit. Clamp-on ammeters are usually used to measure currents ranging from 0.01A or less to 1000A or more.
Step-by-step explanation:
An ammeter is used to measure the rate of flow of electric current in a circuit. It must be connected in series with the measured circuit component. To measure currents ranging from 0.01A or less to 1000A or more, clamp-on ammeters are usually used.