in case of:

A. 表条件(如果,万一)

1. In case of fire, ring the alarm bell. 如有火灾,请按警铃。

2. In case of failure, their position would be perilous in the extreme. 万一失败,他们的处境将是很危险的。

B. 表原因或否定的目的(因为可能、以防、以备)

1. The wall was built along the river in case of floods. 沿河筑了堤，以防洪水。

2. Keep an umbrella in case of rain. 带把雨伞,以防下雨。

in the case of 表示“就……而言”“至于”“在……情况下”：

1. Poverty depresses most people; in the case of my father it was otherwise. (Wood) 贫穷会把大部分人压垮；但对于我父亲来说，情况可就不同了。

2. In the case of a physical change, no new substance is formed. 就物理变化而言,并不产生新物质。

请做下面的英语试题：

I left for the office earlier than usual this morning ____ traffic jam.

A. in line with B. for the sake of C. in case of D. at the risk of(全国六级,91.6-51) case $^{9}$