Correct Option: D

cowardly (Adjective) : lacking courage ; having no courage
indomitable (Adjective) : not willing to accept defeat, even in a difficult situation; very brave and determined
adamant (Adjective) : determined not to change your mind
certain (Adjective) : that you can rely on; happening to be true
arrogant (Adjective) : behaving in a proud, unpleasant way