Many people believed the fake news,so the panic _____across the whole country.

set off v. 出发, 动身, 使爆炸, 引起, 使爆发, 抵销, 分开, 衬托
got off v. 确保 下车 生气 受到惩罚 结识 进攻 一开始 熟络 逃脱
参看例句I had no sooner got off the ship than I was assailed by a man who wanted to sell me a diamond ring.
我刚刚下了船，一个想卖给我钻石戒指的人便向我发动了进攻。
所以我觉得应该是取了上述进攻的意思吧~~~仅个人观点~~~

1. If you asked me which was the worst answer, my reply would be B. "Got off" is a correct
answer, for sure; however, there's nothing wrong with "set off" being the answer.

2. This must be a sentence written by a Chinese teacher of English. For one thing, native
speakers of English normally wouldn't say "the panic", in this sentence and in other situations;
for another, they don't design exercises like this at all. Unfortunately, many Chinese teachers
of English are in the habit of designing questions of this kind to befuddle others as well as
themselves. The end result is low efficiency in the teaching and learning of English.

you set off the panic

panic can not set off itself