Which of the following factors is the main cause of disputes between countries in North America over rights to natural resources?

Their location relative to each other
The distribution of their populations
Climate change and flooding
Access to existing railroads

Their location relative to each other

Explanation:

It is very common for natural resources to be tied with the local communities in North America. People get their income and identity from these natural resources. When certain countries take interest in another country's natural resources, this causes disputes and conflicts that can be exacerbated. This is the reason why struggle over territories happen most of the time. Countries compete with each other and it is mainly due to the natural resources and their relative location.  

the allies' desire to seek retribution for germany's actions