Problem: John has been hearing about climate change for last couple of years. He wants to understand the science behind climate change. For that, he picked up two eras in earth's history, era A and era B. Era A was hundred thousand years ago, and era B is in the present day. He now wants to compare these to eras to understand the change in climate better. Given the paragraph above, please answer correctly the following question: Would era B have more or less carbon dioxide in the air than era A?

A: more

Problem: Vic and Joe studied chemistry in school. Joe studied alkanes, while his friend Vic studied other acyclic hydrocarbons. Given the paragraph above, please answer correctly the following question: Which friend studied less about methane gas?

A: Joe

Problem: David was studying human history. He selected two specific eras of human history, era A and era B. Era A was before humans had invented agriculture. And, era B was after the invention of agriculture. He noticed that human societies had changed dramatically after the invention of agriculture. Given the paragraph above, please answer correctly the following question: In which era food supply was more dependable, era A or era B?

A: era B

Problem: Two teams of runners were training for a 10k. Team Y jogged early in the morning when the weather was cool. Team X started their training in the heat so many team members had problems sweating. Given the paragraph above, please answer correctly the following question: Which team had fewer people that experienced muscle weakness?

A:
Team Y