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

A、Despiteallitsadvantages,nobodywantstohaveasteamcarnow.
B、CycloneTechnologieshasdevelopedanewefficientsteamengine,sosoonsteamcarswillreappearinthemarket.
C、Steamcarshavebeenanimportantpartoftransporthistory,andsomecompaniesarestillmanufacturingthemnow.
D、Steamcarswereoncepopularbutnowonlyremaininthehandsofenthusiasts.