1 如果选B,句子应该是------The dog HAD DIED when we FOUND / SAW it.--------强调死了以后被发现/ 看见.
2 严格地说,The dog was DEAD when we FOUND / SAW it.也是正确的.我看不出这句子有什么语法问题.你的句子哪里来的?其实这一句与下面的句子相同：
1 The dog was lying DEAD on the ground in the garden when we saw / found it.
2 Mary was at home reading when we saw / found her.