When was the ‚Äö√Ñ√∂‚àö√ë‚àö‚à´Clean Air Act‚Äö√Ñ√∂‚àö√ë‚àöœÄ in United States came into force?$

When was the ‚Äö√Ñ√∂‚àö√ë‚àö‚à´Clean Air Act

1.	When was the ‚Äö√Ñ√∂‚àö√ë‚àö‚à´Clean Air Act‚Äö√Ñ√∂‚àö√ë‚àöœÄ in United States came into force?$
A.	1950
B.	1960
C.	1970
D.	1980
Answer» D. 1980