Instruction: answer question  based on the following text

A Products such as shampoo bottles should be purchased from eco-friendly companies. B Airline companies are the great responsible for CO2 emissions in the tourism industry. C Guests often waste energy by misusing the heat and the air conditioner. D A “keyless entry” allows the guest to self-check in, avoiding the manager’s unnecessary trip to the property. E Green energy costs are lower than the regular energy costs.