Problem: Two brothers worked out a few times per week at the same gym. Tim got athlete's food from the gym, but Dan didn't. Which brother picked up the second most common skin disease in the US?

A: Tim

Problem: Lawmakers were debating the pros and cons of Keystone XL Pipeline. One group of lawmakers proposed that the pipeline be constructed. They put their proposal in proposal A. The rival group of lawmakers proposed that the pipeline should not be build. They put their proposal in proposal B. Lawmakers would now have to choose one of the proposals. Which proposal might contaminate the aquifer, proposal A or proposal B?

A: proposal A

Problem: John was interested in climate change issues. To that end, he studied two imaginary situations, case A and case B. In case A, there would not be excessive greenhouse gases in the atmosphere. On the contrary, in case B, the amount of greenhouse gases in the atmosphere would increase dramatically. John realized that the amount of greenhouse gases in the atmosphere has many practical implications. In which case global temperature would be lower, case A or case B?

A: case A

Problem: Students in a chemistry class are performing experiments using two different compounds. The first compound, compound A, has a high number of hydrogen bonds between molecules of the compound. The second compound, compound B, has a low number of hydrogen bonds between the molecules of the compound. Aside from this difference, the molecular structure between the two compounds is similar. Which compound will require less energy to undergo state changes?

A:
compound B