What Rationale Below Best Explains Why Governments Have Used Policies

What rationale below best explains why governments have used policies to encourage greater use of solar panels?

A) Subsidies to consumers to install solar panels help correct negative externalities created by using fossil fuels to generate electricity.
B) Loan guarantees help offset losses of foreign solar panel exporters.
C) There are no costs in using export subsidies allow domestic firms to compete in world markets.
D) WTO safeguard clauses are the best way of encouraging solar panel imports