I would say B. Rivers provided a source of both water and transportation.
This would have to be true, as the great amount of waterways connecting the region would allow for transportation and a supply of water.
Gender Identity: What a person identifies as.
Ex. I was born a female and I identify as a female.
Sexual Orientation: The gender to which someone is attracted.
Ex. I am heterosexual, meaning I am attracted to men.
2/6=0.333333...
Multiply that by 100 to get the percentage.
Answer: 33%