You absolutely right seekmba. This question tests you on 'so' idioms, which are frequently tested on the SC!
The 'so' idiom that is in play here is
so+adjective/adverb+that+clause (subject + verb) --> expresses cause and result!
Example: He was so hungry that he stopped at Burger King. / They ran so fast that they were out of breath by the time they got there.
Note: You can start with the descriptive word too! Ex: So hungry was he that he stopped....
Other 'so' idioms that the SC likes to mess with:
so that --> meaning "in order to"
Ex.I must practice so that I will be prepared for the competition.
not so... as --> inequality comparison
Ex. Tom is not so tall as Joe.
so+adjective1..... as to (be + adjective2)Ex. The politician's statement was so vague as to be ambiguous.
NOTE! This idiom does NOT express cause and result! It is used to STRENGTHEN A DESCRIPTION.
Incorrect: I must practice so as to be prepared for the competition.
In other words, DON'T MIX UP THESE IDIOMS! THEY ARE NOT INTERCHANGEABLE(Many more important idioms are discussed in SC Lessons 9 and 10 at gmaxonline!)
Best,
Sarai
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Sarai
GMAT Verbal Instructor at GMAX
Visit me at www.theverbalcorner.com
If this helped, kindly give Kudos!