Napoleon entered Russia in June, 1812, with an army half a million strong, but leaving in December, 1812, with just less than 30,000 troops.
(A) leaving in December, 1812, with just less
(B) just left in December, 1812, with fewer
(C) left in December, 1812, with just less
(D) left just in December, 1812, with less
(E) left in December, 1812, with just fewer
A sentence can be 100% grammatical correct and yet still have logical problems, and such an answer choice is always incorrect. Folks who treat GMAT SC purely as a test of grammar tend to miss these incorrect choices. For a discussion of these issues with seven other practice problems, as well as the OA & OE for this problem, see:
Logical Splits on GMAT Sentence Correction