Question

Ana is training for a triathlon, a timed race that combines swimming, biking, and running. Consider the following sentence: Ana has only 20 hours this week that she can devote to training. Each hour she spends swimming is an hour that she can't spend biking or running.

Answer 1

Sentence 2 is right.

Step-by-step explanation:

Since Ana is doing the training in which three skills are taught. So it is for sure that if she spends an hour for swimming, that hour cannot be utilized for acquiring other skills such as biking or running. So she has to make a choice and while making a choice she has to forgive other option. That is opportunity cost for her, the next best alternative forgone