In Indian defence and science, what is the correct full form of the abbreviation DRDO, a key organisation responsible for research and development of defence technologies?

Introduction / Context:
This question tests your knowledge of important Indian defence and scientific institutions. Abbreviations such as DRDO frequently appear in newspapers and competitive exams. Knowing their full forms and functions helps you understand defence news and government initiatives more clearly.

Given Data / Assumptions:

• We have the abbreviation DRDO.
• The options offer four different expansions related to defence, research, or development.
• We assume the question refers to the well-known Indian government institution that develops defence technologies.

Concept / Approach:
DRDO is a major organisation under the Ministry of Defence in India. It is responsible for research and development of advanced defence systems, including missiles, radars, and electronic warfare systems. The correct expansion reflects both defence and research and development aspects. Therefore, you need to identify the option that mentions “Defence Research and Development Organisation” accurately and completely.

Step-by-Step Solution:
Step 1: Observe that two options mention “Defence” and two mention “Delhi”. DRDO is associated with defence, not specifically with the city.Step 2: Among the defence-related options, focus on the ones including “Research and Development”.Step 3: Note that the standard and official expansion of DRDO in India is “Defence Research and Development Organisation”.Step 4: Reject options that replace “Development Organisation” with “Deployment” or that associate DRDO with Delhi in a rail context.Step 5: Select “Defence Research and Development Organisation” as the correct full form.

Verification / Alternative check:
The official website and government publications consistently expand DRDO as Defence Research and Development Organisation. Exam guides on Indian polity and science also use the same full form. You can verify this through any standard source on Indian defence institutions, which will mention DRDO in this exact way, often alongside its logo and key projects.

Why Other Options Are Wrong:
Delhi Research and Development Organisation: Incorrect because DRDO is not restricted to Delhi and is not known by this name.Defence Research and Deployment: This changes the last word and does not reflect the core idea of research and development.Delhi Rail Development Organisation: This suggests a railway-related body based in Delhi, which does not match the defence context.

Common Pitfalls:
Candidates sometimes misread abbreviations and select an option just because it sounds official. Another common mistake is to ignore the word “Development” and pick a similar-sounding phrase. When dealing with abbreviations, always match each letter carefully and confirm that the expansion reflects the known role of the organisation in context.

Final Answer:
The correct full form of DRDO is Defence Research and Development Organisation.