Final answer:
The correct answer is c. Frugal, which means being economical and using resources wisely, as advised by Sam's mentor. Other options suggest excessive spending, which is not in line with the mentor's guidance. The correct option is C.
Step-by-step explanation:
Sam's mentor advised him, "You not only must meet your goals, you must also manage your costs and keep them down by being frugal. That means using your resources wisely." The correct answer is c. Frugal.
Being frugal means being economical with the use of resources and not wasting money or materials, which aligns with the advice given by Sam's mentor. This entails careful spending, avoiding unnecessary expenses, and sometimes finding creative ways to save money.
Unlike frugality, being profligate, extravagant, or lavish suggests reckless or excessive spending, which is not reflective of using resources wisely. Therefore, these options contradict the notion of cost management as mentioned in the mentor's advice.