Two types of private solutions to the problem of externalities are

A) charities and the Golden Rule.
B) charities and subsidies.
C) the Golden Rule and taxes.
D) taxes and subsidies.

The Golden Rule (treat others as you would like to be treated) and charities are private solutions to externalities because they rely on individual or private organization actions rather than government intervention. The Golden Rule can encourage individuals to consider the impact of their actions on others, potentially reducing negative externalities. Charities can address externalities by providing goods or services that have positive external effects.