DrVaughan Discovered a Secret Recipe for Barbeque Sauce Which Everyone

Dr.Vaughan discovered a secret recipe for barbeque sauce which everyone really liked. He began selling this in grocery stores. While others tried,no one can seem to master this sauce like Dr.Vaughan. What advantage does Dr.Vaughan have?

A) Secrecy.
B) Monopoly.
C) Causal Ambiguity.
D) Trade Secret.
E) Franchise.