Which detail from the passage weakens the validity of Riggs' argument for keeping the name Mt. McKinley?
a) Riggs disagreed with Sheldon and Browne about the proposed park's name.
b) Mountaineer Belmore Browne referred to the proposed park as "Denali National Park."
c) The legislation officially named the park "Mount McKinley National Park."
d) The Athabaskan words for the mountain translate to "the tall one" or "mountain-big."