The sentence indicates the action was motivated by revenge.
- “Vindictive” perfectly matches, signifying a strong desire for revenge.
- “Malicious” implies intent to harm, but not necessarily revenge.
- “Spiteful” is similar to “vindictive,” though less intense and formal.
- “Callous” denotes emotional insensitivity, not revenge.
Therefore, the best choice is vindictive.
\boxed{\text{Answer: Vindictive}}