GMAT Sentence Correction (SC) | QOTD: In South Korea in the early 2000s

A, B and E are all out for pronoun error. "THEY" do not have a clear antecedent as "THEY" do not refer to companies' assets but should refer to the companies themselves.

The difference in C and D is a comparison parallelism issue.

C. "they had a total of 592 subsidiaries in 2011, nearly twice that of 2002" - subsidiaries "in" is not parallel to "that of"....you cannot say nearly twice "subsidiaries of 2002"

D - "they had a total
...

---