After a Candidate's Recent Interview, You Are Writing a Letter

After a candidate's recent interview, you are writing a letter to decline to offer a position with your organization. Which of the following most effectively delivers the bad news, while avoiding legal liability?

A) I can't believe that we didn't hire you!
B) Although this position was not awarded to you, we appreciate your interest in working for our organization.
C) Although you were definitely our most qualified candidate, we have decided that we don't have a position for a person of your qualifications at this time.
D) Even though your qualifications were outstanding compared to those of our other candidates, we had to offer the position to someone else.