题目请教

Developing nations in various parts of the world have amassed $700 bilion in debts; at stake, should a significant number of these debts be repudiated, is the solvency of some of the world's largest multinational banks.

a should a significant number of these debts be repudiated, is

b should a significant number of these debts be repudiated, are

c should they repudiate a significant number of these debts , are

d if there is a repudiation of a significant unmber of these debts, would be

e if a significant number of these debts will be repudiated, is

答案是a 请nn们解释下为什么

at stake, should a significant number of these debts be repudiated, is the solvency of some of the world's largest multinational banks.

= if a significant number of these debts should be repudiated, the solvency of some of the world's largest multinational banks is at stake.

Two points in this sentence:

1. should somebody/something do something
Should you need any help (=if you need any help) , you can always phone me at the office.

had, should, were for if-clauses

Had I remembered Tomomi's birthday, she wouldn’t be mad at me now.
Note that the word if does NOT appear in the clause when inversion is used:
Had I remembered = If I had remembered

Should you need a hand, I will be more than happy to help you.
Should you need a hand = If you should need a hand

Were I you, I think I would study more for your exam tomorrow.
Were I you = If I were you

Inversion is obligatory.        Used with all verbs.

This is somewhat common on the TOEFL and more common on the GMAT and GRE.

This type of inversion is kind of special. Notice that we can only use this type of inversion when we are using an if-clause. In other words, if is omitted: even though the word if does not appear in the clause, we still have the meaning of an if-clause.

2.  主句倒装. because "at stake" 前置