Note: An annual return that discloses substantial contributors and amounts contributed is required of most organizations exempt from income tax under Section 501, including private foundations.
Exempt from this filing requirement are:

1. Churches,

2. The exclusively religious activities of a religious order, and church, denomination, or interdenominational sponsored foreign mission societies, and

3. Certain organizations that normally have annual gross receipts of $50,000 or less.

Choice "C" is correct. Private foundations must file annual information returns.
Choices "a", "b", and "d" are incorrect, per the above explanation.