How can houses be more energy efficient

9 Ways to Make Your Home More Energy-Efficient :
1. Make sure your walls and attic are well insulated.
2. Upgrade or replace windows.
3. Plant shade trees and shrubs around your house.
4. Replace an older furnace with a high-efficiency system.
5. Improve the efficiency of your hot water system.
6. Replace incandescent light bulbs with compact fluorescent lamps (CFLs).
7. If you buy a new refrigerator, don’t leave the old one plugged in.
8. Take advantage of new tax incentives to improve your home.
9. Schedule an energy audit for more expert advice on your home as a whole.

B is the answer because the area between the velocity time graph and the x-axis is the distance traveled. If you look at the velocity time graph from 0-2, seconds you will see an area of 40m. Only choice B matches that at 2 seconds, the distance traveled is 40m. You can go on to confirm the remaining trip matches that of B by calculating the 2-4 seconds of the velocity time graph area between the x-axis and graph as -40m (negative because area is under the x-axis). Again, it matches graph B, showing that the total distance traveled is 0 for the entire trip.