Which term best defines the customs, traditions, and arts of a group of people ?

CULTURE is the correct answer.

Culture is defined as the ideas, languages, customs, traditions, social behavior and arts of a particular group of people or society. Also, culture is our way of living, traditions, values and the things we believe in.  

(d) rivers.

explanation:

civilizations developed around rivers because their waters provided places to hunt and fish. also, as the rivers flooded, the lands around them became fertile. this allowed them to support farming. this is especially true of the nile river, which flooded the same time each year.

i'd assume india mainly because of how isolated japan was.   plus it is a whole china away.