If My Son Takes a Luxury Cruise Without My Permission

Multiple Choice

If my son takes a luxury cruise without my permission and has the company send me the bill and I pay, I create the impression that I will always pay for this type of conduct. If I fail to inform the company that I will not pay again, this refers to the idea of

A) promissory estoppel.
B) false authorisation.
C) mutual reliance.
D) agent inducement.
E) all of the above.