Answer:
B. a decrease in the unemployment rate
Explanation:
The production possible frontier shows the maximum output of two goods that can be produced using fixed input.
A decrease in unemployment will not result in a shift in the ppf from point 1 to 2, however, am increase in technology will increase productivity in both enterprise causing a shift in the ppf from 1 to 2. The discovery of previously unknown oilfield will also result in an upward shift of the ppf because since both enterprise depend on similar input, there will be more raw material for production hence an upward shift in the ppf.
