grammar question

[haseli22]

Dear native speakers,

Which item is grammatically correct and meaningful to fill the gap?

Despite years of record oil revenues, PDVSA accumulated liabilities of almost $70 billion by last September, up from less than $30 billion in 2006, ..............
a) which the company's financial office reported b) and reported by the company's financial offices
c) when the company's financial reports reveal d) as of the company's financial reports

Thanks.

 

[emsr2d2]

Which one would you use?

I actually find all four unnatural but can make a case for one of them.

 

[haseli22]

I would go for the last item

 

[bhaisahab]

I would go for the last item

That's probably the only possible response but, like emsr2d2, I don't find any of them natural.

 

[Raymott]

Are you sure b) isn't "as reported by the company's financial offices"?