You Are Writing a Refusal Letter to Ryan, Who Recently

You are writing a refusal letter to Ryan, who recently interviewed for a job. Which of the following is the best closing?

A) If you have any questions, Ryan, please do not hesitate to call me.
B) If you had the required five years' experience in social work, we could have included you in the final slate of candidates.
C) Again, Ryan, we truly regret being unable to offer you this position.
D) We wish you all the best in your job search.