Ginny is training for a triathlon, a timed race that combines swimming, biking and running. consider the following sentence: "ginny has only 20 hours per week that she can devote to training for her race." which basic principle of individual choice does this sentence best illustrate? a. many decisions are taken at the margin b. resources are scarce c. all costs are opportunity costs. d. people usually exploit opportunities to make themselves better off

The correct answer is option b.

Explanation:

The statement mentioned in the questions shows the problem of scarcity of resources. It is a basic problem in the study of economics. All the economic problems exist because we have limited resources. These limited resources have alternative uses and we need these resources to satisfy our unlimited wants and needs.  

Here, Ginny has only 20 hours per week for training. Time is a limited resource for Ginny. If she had unlimited time, she could devote more time for training but that's not the case. So she needs to use this limited time to train and get maximum result from this.

answer///a road map;