खालील विधाने पहा :
(a) नायट्रोजन आणि ऑक्सीजन हे वातावरणातील स्थिर वायू आहेत.
(b) वातावरणामध्ये वाराजन्य धुळीचे प्रमाण 9.9% असते.
(c) वातावरणातील वायुरूप नायट्रोजनचा शोध 1772 मध्ये रूदरफोर्ड यांनी लावला.

The correct answer is Option D (Statements (a) and (c) are correct.).

Key Points:
• Scientific Fact Verification:
• Statement (a): Nitrogen (~78.08%) and Oxygen (~20.95%) maintain essentially uniform, constant proportions in the lower homosphere up to an altitude of about 80 km. Hence, they are classified as 'constant / permanent gases' of the atmosphere. (Correct)
• Statement (b): Airborne dust particles and aerosols are highly variable components of the atmosphere, typically making up only a tiny fraction of 1% (usually less than 0.01% by volume/mass), not 9.9%. (Incorrect)
• Statement (c): Scottish chemist and physician Daniel Rutherford discovered and isolated nitrogen gas in 1772, referring to it as 'noxious air' or 'phlogisticated air'. (Correct)
• Therefore, statements (a) and (c) are correct.
• Matches Option (4).
• Key Takeaway: Nitrogen was discovered by Daniel Rutherford in 1772; Nitrogen and Oxygen are constant gases comprising ~99% of dry air.