I also don't understand how this question is a weakening question. If the explanation given above is only a partial one, isn't the question asking me to add more information to strength the argument - which is exactly what answer choice C does?

http://classic.7sage.com/lesson/group-3-group-4/

Yes. When you have a sentence with both a group 3 indicator word (without) and a group 4 indicator word (cannot) you can follow either translation rule just remember to negate the other idea.

A business cannot change its core corporate philosophy without becoming a different corporation.

Group 4 Translation: Cannot

CCCP --> BDC

/BDC --> /CCCP

or

Group 3 Translation: Without

/BDC --> /CCCP

CCCP --> BDC

I'm still very confused on how you calculated B is the correct answer using the numbers 100 and 99...

Is this a whole to part flaw?