for a whole night we still couldn't agree on when to start and where to go for the holi

问题补充：

for a whole night, we still couldn agree on when to start and where to go for the holiday.

A. Discussed

B. Having discussed

C. Discussing

D. Being discussed

答案：

A. Discussed

(答案→)B. Having discussed

C. Discussing

D. Being discussed

解析：B 考察非谓语动词。句义：讨论了一整个晚上，在何时出发，去何地度假的问题上大家仍然不能达成一致意见。主语we和动词discuss是主动关系，应该使用现在分词；discuss动作发生在句子动作之前，应该使用现在分词的完成式。故B正确。