The correct answer is D. New Delhi.
The Research Designs and Standards Organisation (RDSO) is a premier technical organisation of the Indian Railways. It is headquartered in New Delhi, India. The RDSO was established in 1952 with the objective of providing technical support to the Indian Railways. It is responsible for conducting research and development, standardization, testing and inspection, and training in the field of railway engineering.
The RDSO has a wide range of activities, including:
- Research and development in the field of railway engineering
- Standardization of railway equipment and systems
- Testing and inspection of railway equipment and systems
- Training of railway personnel
- Consultancy services to the railway industry
The RDSO is a well-respected organization in the field of railway engineering. It has a strong track record of innovation and has made significant contributions to the development of the Indian Railways.
The other options are incorrect because:
- Vadodara is a city in Gujarat, India. It is not the headquarters of the RDSO.
- Lucknow is a city in Uttar Pradesh, India. It is not the headquarters of the RDSO.
- Chennai is a city in Tamil Nadu, India. It is not the headquarters of the RDSO.