Vatsal7794
I marked ans as D because how can we put inportant information between Comma?
Initially I was confused between C and D but ultimately marked ans as D
This is not a good question. It's a prep company question, and like most prep company Verbal questions, it isn't worth studying. Several posts above have pointed out issues with the "OA" (redundancy and an unclear modifier), but there are others. All of the issues the "official explanation" finds in answer D are worse in the "OA" of C. Answer C is a lot more awkward than D, with the two consecutive interrupting comma phrases. And answer C is not idiomatic English -- you "extend your reach", not "expand" it, and you "implement a strategy"; you don't "apply a strategy".
The bigger problem is that the sentence is meaningless. It's just a lot of jargon words strung together. If I read answer C and ask myself "what is this company's strategy?" I have no idea. The company's "growth strategy" seems to involve growing or expanding (of course it does) and "looking to" (which means "thinking about") doing something else. A strategy is a plan of action; thinking about doing something can't be part of a strategy. I also don't know what "applying global strategies" could even mean.
I don't see a good reason to rule out answer D here -- it has some of the same meaning problems as C, but it seems like a better-written sentence to me. It's not, as the OE claims, unidiomatic. "Looking to" is an English idiom, but "looking at" is also an idiom, with a different meaning. There's no way to tell which meaning is intended here. There's also no way to tell whether the company is "using local insights" to both "expand its global reach" and "apply global strategies", or if it will only use local insights to do one of those two things. We'd need to be psychic to guess the meaning the author intends, and you don't need to be psychic to pick the right answer on real GMAT SC questions.
As always, I'd suggest studying exclusively from official Verbal questions -- prep company Verbal questions are almost always problematic for one reason or another.