The diagram illustrates demand for and supply of eye tests offered by opticians. Which policy would allow the government to raise the number of eye tests from OQ1 to OQ2?
- Aa maximum price of OP3 per test
- Ba minimum price of OP2 per test
- Ca subsidy paid to opticians of P3-P2 per test
- Da subsidy paid to opticians of P3-P1 per test