Read the passage carefully.

To the south and southeast of China are the Himalaya Mountains. These are the highest mountains in the world. They provided a nearly impassable border for Ancient China, keeping the area isolated from many other civilizations. They were also important to Chinese religion and were considered sacred.

– “Ancient China: Geography,”

Ken Nelson

Using context clues, which phrase best defines the word impassable?

separate or apart
tall and forbidding
unable to be crossed
of divine or holy origin

unable to be crossed