Question

a reason that countries trade with each other is
to help their neighbors.
to get products they cannot produce.
to sell goods they do not need.
to share excess resources.

Explanation:

International trade is primarily driven by the principle that countries lack the resources, climate, or capability to produce all goods their population needs. The other options are not core, primary reasons: helping neighbors is a secondary, non-economic motive; countries sell surplus (not unneeded) goods, and sharing excess resources is a subset of broader trade drivers, not a main foundational reason.

Answer:

to get products they cannot produce.