A country tends to specialize in certain products primarily due to the resources of the nation. This includes factors such as the availability of natural resources, labor force skills, climate, and geographic location, which can all influence what goods and services can be produced most efficiently. Additionally, other factors like the ability to trade with other nations and the economic incentives or profits associated with specific industries also play significant roles in specialization.
In summary, while all the options provided can influence specialization, the primary driver is typically the resources available to the nation.