The correct option is C A reduction in the labour unemployment rate.
A reduction in the labour unemployment rate, creates 'employment' an increase in employment shifts production from inside the PPC either to the PPC curve or closer to the PPC curve. While rightward shift in PPC or economic
growth, per se, is possible in the following circumstances-
1. Improvement in overall technology
2. Greater capital formation
3. Increase in population growth / labour force