Which of the following circumstances causes an increase in fuel consumption?
A)Driving with the vehicle windows up.
B)Driving with tires that have no tread.
C)Driving with the vehicle heavily loaded.Correct
# Explanation
A vehicle loaded with extra weight requires more energy to move, accelerate and maintain speed, which directly increases fuel consumption. This is one of the most significant factors affecting engine efficiency. Keeping the vehicle free of unnecessary load is a recommended practice to optimize fuel consumption.