Please check the correct statements.

Select $2$ correct answer$($s$)$

A$)$ Externality $($positive or negative$)$ leads to market failure

B$)$ Res Communis rights are rules that specify who can access a particular or service.

C$)$ Because everyone can consume the same amount of a non$-$rival resourd horizontally sum the marginal value curves.

D$)$ Externalities $($positive$/$negative$)$ are not beneficial for society.