The correct answer is the last option, TRADE IS LIMITED BECAUSE OF THE PHYSICAL BARRIERS ON LAND AND WATER.
It is known that China has a geographically diverse landscape and this affected China’s development because it was so hard to cross the large Gobi and the Taklamakan deserts that it would easily take days to cross. The same happens with the Himalaya Mountains, difficult to climb. Just to mention those two, also, the same thing would happen with all of the other China’s landscape characteristics that are so big and time consuming to cross or climb that people wouldn’t bother to try.
That is how geography impact trade between China and India. But now with the SILK ROAD (built in China) which are a series of trade routes established that connects China with other continents as well as countries, it is better and easy to trade.