Two men, Barry and David, and two women Ann and Cathy are doctors. One is a surgeon, one a dentist, one an optometrist, and one is a general practitioner. They are seated around a square table, with one person on each side.
- Barry is across from the dentist.
- David is not across from the surgeon.
- The optometrist is on Ann's immediate left.
- Cathy is the general practitioner.
- The surgeon and general practitioner are married to each other.
- The general practitioner is not on Cathy's immediate left.
- The general practitioner is across from the optometrist.
Which of the following must be true?
