A. forgetful
B. forgiving
C. obedient
D. timid
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
