The correct answer is D) Isolation from other early civilizations.
A result of the physical geography of ancient China was the isolation from other early civilizations.
One of the factors that isolated China from the outer world were its many natural barriers. Geography played a key factor in this isolation for many years. For instance, the Himalayas mountain range, Mount Everest, Gobi Desert, Yellow Sea, Taklamakan Desert, and the Pacific Ocean. This natural barrier also helped China kept invaders away.