27. Which of the following describes a "negative effect of China's geographic features forming natural barriers? a. China's geographic features limited expansion into other lands and isolated them from other cultures.

b. China's geographic features made it easier for Chinese civilizations to trade with outside civilizations.

c. China's geographic features made it easy for outside invaders to attack.

d. China's geographic
features promoted expansion into other lands and made it easier to share ideas with other
cultures.