If a Correlated-Groups T Test and an Independent-Groups T Test

Multiple Choice

If a correlated-groups t test and an independent-groups t test both have df = 16, how many subjects were in each study?

A) There were 16 subjects in both studies.
B) There were 17 subjects in both studies.
C) There were 17 subjects in the correlated groups and 18 subjects in the independent groups.
D) There were 18 subjects in the correlated groups and 17 subjects in the independent groups.