Which of the following cases led to the legalization of same-sex marriage in all 50 states in the United States on June 26, 2015?

A) United States v. Edith Windsor
B) Ariad v. Lilly
C) Obergefell v. Hodges
D) Bilski v. Kappos

Obergefell v. Hodges was a landmark case in which the Supreme Court of the United States ruled that same-sex marriage is a fundamental right under the 14th Amendment of the US Constitution, and therefore legal in all 50 states. The case was brought by a group of plaintiffs led by James Obergefell, who sought the right to be listed as the surviving spouse on the death certificate of his partner, John Arthur, who had passed away from ALS.