The correct option is
A Maiden
Option B - 'Extempore' means done or said without any preparation or thought. Thus option B is incorrect.
Option C - 'Opener' is a device for opening closed containers. Thus option C is incorrect.
Option D - 'Preface' is an introduction at the beginning of the book explaining its purpose. Thus option D is incorrect.
Option A - 'Maiden' means the first attempt at something. Thus option A is the correct answer.
'A person's first speech - Maiden'