民用爆炸物品从业单位依法应当在规定的时间内向公安机关报告从事相应从业活动的资质、基本活动、民用爆炸物品交易流向等三类基本情况的治安管理要素信息，由公安机关登记、备查、纳入日常管理，并作为申请后续从业活动许可的依据。

Annie Jump Cannon, ________ discovered so many stars that she was called "the census taker of the sky".

A．a leading astronomer,

B．who, as a leading astronomer,

C．was a leading astronomer,

D．a leading astronomer who