Which sentence best describes the author's opinion about steam cars? （ ）

A、Despite all its advantages, nobody wants to have a steam car now.
B、Cyclone Technologies has developed a new efficient steam engine, so soon steam cars will reappear in the market.
C、Steam cars have been an important part of transport history, and some companies are still manufacturing them now.
D、Steam cars were once popular but now only remain in the hands of enthusiasts.