Why Was the Supreme Court Decision in Munn V

Why was the Supreme Court decision in Munn v. Illinois significant to understanding the power of government to regulate industry?

A) It was a ruling that lasted for a century and denied the right of state and local governments to regulate industry.
B) It upheld the sweeping power of the federal government to regulate any industry in any fashion it saw fit.
C) It denied the federal government any power to regulate any industry, as Big Business was seen as untouchable.
D) It upheld the right of state and local governments to regulate industry essential to the public interest.
E) It decided that all government regulatory power over industry rested with city and town governments.