Which statement is a similarity between electricity and water?

• A. They can be stored in a tank
• B. They taste sweet
• C. They produce light
• D. They require a source

Answer: (D)

Both electricity and water move because there is a driving force behind their movement. Water flows downhill or under pressure because gravity or a pump provides energy to push it through pipes. Electricity flows when there is a source of electrical energy—like a battery or generator—that creates a voltage difference and pushes electrons through a circuit. So the common similarity is that a source is needed to drive the flow.

Other options don’t capture this shared idea: tasting sweet isn’t related to how either moves; producing light isn’t a universal property of electricity or water; and water can be stored in a tank, but electricity isn’t stored in a tank in the same way.