Rule: Unrelated business taxable income must be derived from an activity that constitutes a trade or business that is regularly carried on and is not substantially related to the organization's tax-exempt purpose. Both of the above options appear to be substantially related to the organization's tax-exempt purpose and, therefore, are not taxable. Choice "D" is correct, per the above explanation.Choices "b", "c", and "a" are incorrect, per the above explanation.
