In His 1880 Speech, What Idea Did Robert Ingersoll Promote

In his 1880 speech, what idea did Robert Ingersoll promote?

A) Industrial manufacturing should be confined to specific districts to reduce air pollution.
B) People should not be permitted to burn coal to heat their homes.
C) Limiting air pollution emitted from factories of the time.
D) Industrial smoke was a sign of prosperity and was thus highly desirable.