Choice "C" is correct. The private foundation status of an exempt organization will terminate if it becomes a public (50% type) charity.Rule: Section 509 private foundations include all Code 501(C)(3) organizations, except:

1. Max 50% charitable deduction donees

2. Broadly publicly-supported organizations

3. Supporting organizations

4. Public safety organizations

Choice "a" is incorrect. A private foundation can have a charter that limits its exempt purpose.

Choice "d" is incorrect. A private foundation is not required to distribute all of its net assets to one or more public charities.
Choice "b" is incorrect. Foreign corporations may qualify as a private foundation.