Answer :
The correct answer is C) Cayuse Indians wanted to rob the mission,
The statement that was not a contributing factor to the Whittman massacre was that Cayuse Indians wanted to rob the mission.
On November 29, 1847, Cayuse Indians violently murdered Marcus Whitman and his wife Narcissa. The Whitmans were missionaries from the Presbyterian Congressional of Foreign Mission, in New England. The Cayuses strongly opposed to the evangelistic efforts of the Whitmans and tensions began to arise. After the Cayuses murder them, they took hostages. The United States government had to intervene to resolve the incident.