Although the Argentine ant is neither poisonous nor predatory, individual colonies cooperate in a super-colony so large that its collective appetite can become a competitive threat to bird, lizard, and other insect populations.

A. individual colonies cooperate in a super-colony so large that its collective appetite can become a competitive
B. individual colonies cooperate in a super-colony of such size, its collective appetite can become a competing
C. individual colonies cooperate in a super-colony so large as to cause its collective appetite to become a competitive
D. such is the size of the cooperative super-colony comprising individual colonies, its collective appetite can become a competing
E. there is so much size to the individual colonies' cooperative super-colony that its collective appetite can become a competitive

This is what OE for C is frm Mgmat...

The construction "so x as to y," presented here as "so large as to cause..." is a suspect idiomatic form, one that is not preferred by the GMAT. Moreover, the meaning is changed; "so large as to cause..." means that the outcome definitely happens. However, the original sentence only indicates that the "collective appetite CAN become..."

My q: So X as to Y is wrong on GMAT?

OA is A