一个很难解释的英语单选题-----------高手帮忙
upon a true story,the film was very successful in our country.
A：Based B：To base C：Basing D：Being based
从句的省略.从句的主语是the film与base之间存在被动关系.
还原原句：Because it was based upon a true story.the film was very successful in our country.
译：以真实故事为基础,这个电影在我国取得很大成功.
我怎么看不出被动还是主动呢?如果直译的话,应该是“因为电影是被以真实的故事为基础”,真别扭,
如果不纠结主动还是被动，