His vindictive nature often came up for comment among his friends.

Answer: Option B

vindictive : having or showing a strong or unreasoning desire for revenge.
forgetful : apt or likely not to remember.
forgiving : ready and willing to forgive.
obedient : complying or willing to comply with an order or request; submissive to another's authority.
timid : showing a lack of courage or confidence; easily frightened.


Antonym of vindictive is forgiving