The correct option is D unfeeling
The underlined word 'callous' means 'an insensitive or cruel disregard for others'. It refers to the character or nature of a person or a group.
Option C: 'Unfeeling' means 'unsympathetic, lacking sensitivity'. It expresses the meaning of 'callous'. Hence C is correct.
Option A: 'Cursed' means 'damned or doomed'. It does not refer to a behavioural trait.
Option B: 'Kind' is a positive trait that refers to someone who is generous and considerate. It's the opposite of 'callous'.
Option D: 'Passive' means 'unresponsive, submissive'. It does not explain the underlined word.
Hence options A, B and D are incorrect.