Correct answer: (a) Astrology
Explanation
- A
Astrology
Jayant Vishnu Narlikar, the astrophysicist, has argued that astrology does not meet the tests of a science: it lacks a physical mechanism, fails controlled tests and is not revised by evidence. Among the listed fields, astrology is the one he has not accepted as science. This option is the official key.
- B
Astronomy
Astronomy is the observational science of celestial objects and is Narlikar’s own professional domain. He treats it as science. This option is not the key.
- C
Cosmology
Cosmology is the scientific study of the origin and large-scale structure of the universe, to which Narlikar has contributed. It is regarded as science. This option is not the key.
- D
Nanotechnology
Nanotechnology is an applied science and engineering field. Narlikar’s critique of astrology does not place nanotechnology outside science. This option is not the key.
Summary. Official key is (a) Astrology. Narlikar has publicly separated astronomy and cosmology, which are empirical sciences, from astrology, which he holds has not earned scientific status. Astronomy, cosmology and nanotechnology are recognised scientific or technical fields. Only astrology is the one he has so far not considered a science, as the stem asks.