A report claims that the greenhouse effect started with the Industrial Revolution in Europe when gases, such as carbon dioxide, were first released into the atmosphere in large amounts. These gases trap heat within the atmosphere and raise the temperature of Earth. What is a weakness of this argument?

Select one:
a. Carbon dioxide is a gas used by plants to make food and not a greenhouse gas.
b. These gases were present in the atmosphere well before the Industrial Revolution began.
c. The report does not mention any experiments that the author carried out to check his facts.
d. The Revolution happened over 200 years ago and Earth should have been much hotter by now.