Which URL ending would identify a website for a charity?

.org

Explanation:

A .org website is the URL used for organizations. It is a top level domain, and frequently used by giant bodies even. It is a truncated from the full word, organization.

Even charity websites use .org frequently well. The .org domain was initially intended for non profit organizations, until few months ago during which the restrictions were lifted. It is frequently used by communities, schools, and of course, charity organizations or NGOs.

after the roman empire, the catholic church began to unify by taking on many duties of a government.

the answer is definitley b!