Which of the following is a unit of electric current in the SI system?

• A. Ohm ($\Omega$)
• B. Volt (V)
• C. Watt (W)
• D. Ampere (A)

Answer: (D)

Verified step by step guidance

1. Understand that electric current is the flow of electric charge per unit time, and its SI unit is defined based on this concept.
2. Recall the SI base unit for electric current is the Ampere (A), which measures the amount of charge passing through a conductor per second.
3. Recognize that Ohm (Ω) is the unit of electrical resistance, Volt (V) is the unit of electric potential difference, and Watt (W) is the unit of power, none of which measure current.
4. Confirm that the Ampere (A) is the only unit among the options that directly quantifies electric current in the SI system.
5. Therefore, identify Ampere (A) as the correct SI unit of electric current.