单选题 ______ nobody was very enthusiastic about it, they decided to cancel the trip.
A. Provided B. On condition that
C. See to it that D. Seeing that

【正确答案】 D

【答案解析】Seeing that…“鉴于；由于”，用来表示比较明显的原因。A．Provide(that)和B．on condition(that)在……情况下，倘若，用来引导条件状语从句；C．See to it that务必……，一定注意到……。