Please choose the correct answer to the question: Burning coal and natural gas are ways to produce electricity. Both coal and natural gas are nonrenewable resources. Which is an example of producing electricity using a renewable source of energy?

Answer1: using food pieces to make compost Answer2: gliding a boat through the water using sails Answer3: putting an energy-saving lightbulb in a lamp Answer4: heating a home with energy collected by solar panels

Answer format: answer1/answer2/answer3/answer4
Answer: answer4