Since the end of World War II, an increasing share of world economic output is being traded among nations.Which of the following is not a main contributor to that increase?

Group of answer choices

An economic shift in many countries from producing services (which are non-tradable) to producing manufactured output (which is tradable)

A policy focus to increase countries' interdependence on one another, such as decreasing tariffs.

Improvements in transportation infrastructure such as the containerized box.

Technological innovation that allow for instantaneous communication.