Explanation:

- Elliott and Merrill described law as "more clear mores," stating that laws are mores with the backing of state sanction. This means laws have a formal, enforced authority, whereas mores are powerful customs but lack state enforcement.

- K. Young: He emphasized the role of social norms and control but is not directly associated with this particular definition.

- E. A. Ross: Known for work on social control and mores, but did not specifically define law as "clear mores backed by state sanction."

- Lumley: Not known for this particular theory about mores and law.

- Elliot and Merrill: Correct Answer. They explicitly stated that laws are those mores which have the additional backing of state authority and must be obeyed.