Which of the following methods can be used to measure power in a single phase circuit without using wattmeter?1. One voltmeter, one ammeter2. Two voltmeters, two ammeter3. Three voltmeters4. Three ammeters

• A. 1 and 2 only
• B. 2 and 4 only
• C. 1 and 3 only
• D. 3 and 4 only