Explanation:

- 'Cataract' is a medical condition related to the eye.

- Ophthalmology is the branch of medicine that deals with eye conditions.

- This makes 'Cataract' related to 'Ophthalmology'.

- 'Neurosis' is a mental health condition involving stress, anxiety, or other psychological issues.

- Psychology is the field that studies the mind and behaviors, including neuroses.

- Neurology deals with disorders of the nervous system, not specifically psychological conditions.

- Sociology studies human social behavior.

- Biology is the study of living organisms, unrelated to specific mental conditions.

- Correct Answer: Psychology