问题
选择题
Only after they had discussed the matter for several hours _______a decision.
A they reached B did they reach C they reach D do they reach
答案
答案：B
本题考察only前置的倒装句。Only引导状语从句前置，主句主谓要部分倒装。又因为从前文中的"had discussed"判断出是过去时间，故选B；