Mick Starts a Business to Market Nationally Long-Distance Phone Time

Mick starts a business to market nationally long-distance phone time as Mick's Minutes.Registering his trademark with the U.S.Patent and Trademark Office provides nationwide protection for the mark

A) if the mark is currently in use.
B) only if the mark has not yet been used.
C) only if the mark will not be used for at least six months.
D) only if the mark is currently in national use.