A Has Been Using the Name Pedro Since Birth Although

A has been using the name Pedro since birth although his record of birth shows that his name is Juan. He is now 25 years old and about to take the Bar Exams. How can he use the name Juan when he will take the Bar Exams?

A) He has to file a petition for change of name.
B) He can go to the Local Civil Registrar and file an administrative petition for change of name.
C) He can just use it with an affidavit that Pedro and Juan refer to one and the same person.
D) He cannot change his name because of lapse of time.