What element of geography would apply to the spread of Confucianism

It was an eastward trend that established Confucianism.

Explanation:

The establishment of Confucianism was happening to the east.

At first it happened in India that the groundwork was laid in terms of being inspired by Buddhist thinking.

Then it reached its current form in China.

From there on it was taken up by the Koreans, Japanese and others in the far east too

One difference in here is the fact that this also reached other places in the west of China through the silk road and traveled through it, albeit without much success as an idea.