The diagram shows the production possibility frontier of an economy shifting outwards from PPF1 PPF_1\,PPF1 to PPF2PPF_2PPF2.
Which of the following policy initiatives is most likely to cause the shift shown in the diagram?
A reduction in the central bank's base interest rate to stimulate consumer borrowing and household spending
Government tax incentives designed to encourage private sector investment in research and development (R&D)
An increase in state welfare benefits to support low-income households and boost aggregate consumption
A reallocation of existing labour from agricultural production to service industries with no change in overall productivity