6. What is the author's purpose for including information about steam- and gas-powered
cars?
A to explain how steam- and gas-powered cars influenced the design of electric cars
B to describe how steam- and gas-powered cars transformed over time into electric cars
C to prove that electric cars were similar in operation and design to steam- and gas-powered cars
D to show that electric cars lacked the early problems associated with steam- and gas-powered cars