The Clean Air Act of 1963 was an improvement over the Air Pollution Control Act of 1955 because it _____.

provided twice as much money for the study of air pollution

set limits on emissions from factories

set limits on emissions from vehicles

prevented the deforestation of national parks

Verified Answer :

The Clean Air Act of 1963 was an improvement over the Air Pollution Control Act of 1955 because it "set limits on emissions from factories," since factories had largely gone without regulation before this. 

Correct answer:

set limits on emissions from factories

The Air Pollution Control Act of 1955 was the first federal legislation related to air pollution.

The Clean Air Act of 1963 established a federal program within the US Public Health Service. and authorized the investigation of techniques to monitor and control air pollution in factories.