Every organization or trust exempt under this chapter, except as provided in this article, is subject to the tax imposed upon its unrelated business taxable income, as defined in Section 23732, as follows:

1. (a) Corporations (other than banks and financial corporations), associations, and business trusts are subject to the tax imposed under Section 23501.

2. (b) Trusts are subject to the tax imposed by subdivision (e) of Section 17041.

   This section applies to taxable years beginning after December 31, 1970.