169.Because the enemy's new ship is the quietest and it is therefore the most elusive submarine, it is being increasingly viewed by the millitary as a threat to security.

A.and it is therefore the most elusive submarine, it is being increasingly viewed

B. it is therefore the most elusive submarines,and it has increased the view

C.and therefore the most elusive submarine,it is being increasingly viewed

D.and therefore it is the most elusive submarines,there is an increasing view

E.therefore being the most elusive submarines,it is increasingly  viewed

感觉being有问题 错误答案的标志 还有看了过去的讨论 有一些不同的观点

我认为在A 中  两个it 指的不是一个东西 第一个只得是ship 而第二个似乎要表达 指代前面it is therefore the most elusive submarine这个事 所以错了 而不是说没有指代对象