Marginal thinking is best demonstrated by:
choosing to spend one more hour studying economics because you think the improvement in your score on the next quiz will be worth the sacrifice of time.
deciding to never purchase a coat made with animal skins or furs acquiring the information relevant to a choice before making that choice measuring all of the costs of a meal against all of the benefits when deciding whether to order a second milkshake

choosing to spend one more hour studying economics because you think the improvement in your score on the next quiz will be worth the sacrifice of time.                                                        

Explanation:

Marginal thinking: In economics, the term "marginal thinking" is described as a process that requires or needs the "decision-makers" to figure out whether the profit related to one or more than one unit of something is considered as greater than its actual cost.

In other words, it described the process that states the number of extra resources that are being considered as worth.

you answered your own : -/