Entity O is a business entity formed under the laws of country X that has an income tax treaty in effect with the US. O is treated as a partnership for US tax purposes but is treated as a corporation under the laws of X. O's partners are M, a corporation organized under the laws of country Y that has an income tax treaty in effect with the US, and T, a corporation organized under the laws of country Z that has an income tax treaty in effect with the US. Article 12 of the US-X income tax treaty provides for a source country reduced rate of taxation on royalties of 5 percent. Article 12 of the US-Y income tax treaty provides that royalty income may only be taxed by the beneficial owner's country of residence. O receives royalty income from US sources for licensing cookie trademarks that is not ECI. Who's entitled to treaty benefits?