What is the most logical next event?

How to save money on utility bills
Adjust your thermostat.
Heating and cooling can be roughly half of the utility bill costs in your home. Keep your thermostat warmer in the summer and cooler in the winter.

Options are: a. According to the official homeowners association, much of the utility bill should follow this format : Change your water bill every 14 to 45 days. Change your furnace every 3 to 4 months, if it is not already turned on during the day. b. Many home owners limit their thermostats to a reasonable range from 9 to 12 degrees fahrenheit (24 to 36 degrees celsius). For example, you may have a thermostat of 12 to 24 degrees fahrenheit (24 to 36 degrees celsius). c. There are more than two heating elements in your home, one colder than the other. You will have to adjust each one the same number of times to ensure it stays in place. d. You can also get a programmable thermostat to save money. When no one is home, you can keep your settings closer to the outdoor temperature to avoid heating or cooling an empty place.
d.