He tried to cajole her, but it was in vain.

Answer: Option B

Enjoin : instruct or urge (someone) to do something.
Coax : gently and persistently persuade (someone) to do something.
Rejoice : feel or show great joy or delight.
Inspire : fill (someone) with the urge or ability to do or feel something, especially to do something creative.
Cajole : persuade (someone) to do something by sustained coaxing or flattery.

Synonym of Cajole is Coax