Four couples—the Potters, the Regans, the Stewarts, the Wilsons—are seated evenly spaced about a circular table.
The Regans do not sit next to the Stewarts.
The Stewarts sit next to each other.
Mr. Potter sits directly opposite Mr. Wilson.
If Mr. Regan sits midway between Mr. Potter and Mr. Wilson, then which of the following persons could sit directly across the table from Mr. Regan?