Answer: Increasing fuel efficiency can help us both financially and ethically
Step-by-step explanation:
The options include:
a. Using oil as a fuel has negative consequences for the environment.
b. More efficient cars are interesting to many people not learning to drive.
c. We make change happen by taking an interest in the choices we have.
d. Increasing fuel efficiency can help us both financially and ethically
The best way to conclude the essay will be "Increasing fuel efficiency can help us both financially and ethically".
Option A cannot be the answer as the essay will be concluded by writing in the negative impact of fuel efficient cars which isn't appropriate since we are discussing about the benefits.
Option B and C can't be used to conclude the essay as the benefit isn't discussed.
Option D is the best option as it gives us reason why we need to increase fuel efficiency.