In order to say that carbon dioxide caused global warming scientists had to a. come up with a mechanism that made sense and test the steps in the mechanism to see if they were accurate b. make a good argument for climate change and publish it in a research journal c. make a graph that showed that carbon dioxide and the earth’s temperature were increasing at the same time d. review the weather patterns on earth to see if they were changing over time

Option A.

Explanation:

Option A directly tests the cause and effect. Option B simply argues it argumentatively without any solid evidence to show cause and effect. Option C only shows correlation and Option D only shows correlation as well.

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.