C
这是强调句：“是团队合作使我们活下来”
注意强调句的固定句式：
“It is / was + 被强调部分 + that + 其它”.
如 It is Tom that likes this colour.(强调主语) / It was my mother that I gave the present to yesterday.(强调宾语) / It was because I fell asleep that I missed the TV play.(强调状语) / It was into the schoolbag that he put his books.(强调补语)
希望我的回答能够帮到你,