Which of the following was not one of the grandparents of Arwen, according to J.R.R. Tolkien's works?

Elrond was Arwen's father, he being the son of Earandil and Elwing, and the brother of Elros. Elrond and Elros, being half Elven, were given the choice of mortality or immortality, Elrond choosing the life of an elf, and his brother choosing that of men. Elros became a king of men, and founded the dynasty that, many years later, resulted in Aragorn becoming King of Gondor. Elrond's wife Celebrian, Arwen's mother, was the daughter of Celeborn and Galadriel.