The thirteen original British colonies in North America, some formed as commercial ventures, others as religious havens, each had a written charter that set forth its form of government and the rights of the colonists.
A. some formed as commercial ventures, others as religious havens, each had a written charter
B. some being formed as a commercial venture, others as religious havens, all of which had written charters
C. some that formed as commercial ventures, others as religious havens, all had written charters
D. with some being formed as a commercial venture, others as religious havens, all had a written charter
E. with some formed as commercial ventures, while others as religious havens, each had a written charter
It's a GMATPRP question, OA is A.
But I think A is a run-on sentence, E seems more appropriate.
Can any one help to explain?