What declined in the 1970 because of competition form foreign nations? online shopping, outsourcing or industrial manufacturing

The answer is definitely INDUSTRIAL MANUFACTURING.

Why?
1. During the 1970s Recession, Western countries that once flourished Post World war II experienced severe stagflation wherein simultaneous high unemployment rate and high inflation rate occurred.

2. Coinciding with this recession is the growth of developing economies with cheaper labor. Globalization is also on the rise that increased imports in the western countries. 

3. These two events led manufacturing companies to stagnate because of the lack of competitive spirit in the industry, looming costs and competitive labor from Asian countries. 

4. The once bountiful industry of manufacturing declined together with employment decline as companies started to downsize. Together with high unemployment rates and high inflation rates, the income inequality in western countries widened. People had the lesser purchasing power that further led to significant decline in demand for goods.