求英语达人【事后附上财富悬赏500分】英语解释选择题

求英语达人【事后附上财富悬赏500分】英语解释选择题
Being buried in the mine was terrible ___ the 33 Chile miners never gave up in a time of trouble.
A.although B.so C.for D.but
这道题的答案是【A还是D?】.
中文解释为：这个句子是让步状语从句.因为在困难中智利矿工并没有放弃,所以选【D or 】.【D or 】表示转折..所以选择【】.
要用英语解释上面的话.
e.g:The answer to this question is ___.This sentence is 【让步状语从句英文】.Because the Chile’s miners didn’t give up when they are in trouble.So we must use a word which means trasition【这个‘转折’拼对了么】.So we should choose ___.

A Adverbial Clauses of Concession transition A