16. What factors explain why the United States' most important trade partner is Canada? a. Culture and lack of resources
b. Climate and physical geography
c. Location and level of development
d. Migration and urbanization

C

Explanation:

location and level of development

d is the logical answer but im not a 100% sure

answercharacteristics of place include things like economic activity, architecture,and culture,all of which are human elements that alter or can be influenced by the environment;