Explanation:

- Relative deprivation is a concept used to describe the feeling that one is worse off compared to others, even if their actual condition hasn't changed.

- Option 1: Samuel A. Stouffer ()

- Correct Answer. Stouffer and his colleagues first used the term "relative deprivation" in their studies of American soldiers during World War II.

- Option 2: R.K. Merton

- Merton expanded on Stouffer's work and applied "relative deprivation" to other areas of sociology.

- Option 3: Herbert Hyman

- Hyman worked on reference groups and contributed to related sociological concepts but didn't originally coin the term.

- Option 4: K. Davis

- Davis is noted for demographic and population studies, not for originating "relative deprivation".