All hope of finding the missing plane ______,the relevant authorities declared the crew and passengers ______．
A.giving up; were killed B.giving up; killed
C.given up; killed D.given up; killing
选项是C.
given up与逻辑主语构成独立主格结构,在句中作状语；declare sb./sth.to be+adj./过去分词,表示“宣布……是”,其中to be可以省略.