It was reported that the passenger ship was sailing eastwards in the Atlantic Ocean ____ its captain

and some passengers on board____ something supposed to be a UFO flying overhead.      [ ]

A. while; caught sight of                

B. when; caught sight of  

C. as; saw                            

D. since;  caught a sight of

证券公司的工作人员并不都须具有证券从业人员资格。( )