I have a question about ACT 74F ENGLISH SECTION #17

I have a question about ACT 74F ENGLISH SECTION #17

I was able to eliminate A/B, but I got stuck betwen the choices C/D.

The answer is C. But I thought C was wrong because after eliminating -160000 in all- , you are left with a dependent clause and an indepenent clause. There fore, you will need a comma between clasues. The C is as follows:

To amass the staggering number of corks need to construct the boad–165,231 in all-- Pollack convinced the staff of several restaurants.

anyone as any ideas?

I chose D , but I now know that the number and in all need to be put together.