please also provide a detailed explanation. I have no idea how to get the correct result. Thank you!!!!

Scenario 17.1 Consider the information below: For Group A the cost of attaining an educational level y is c A(y) = $6,000y and for Group B the cost of attaining that level is CB(y) = $10,000y. Employees will be offered $50,000 if they have y < y* , where y* is an education threshold determined by the employer. They will be offered $130,000 if they have y > y*. 5) Refer to Scenario 17.1. The highest level of y* that can be set and still have the high-productivity people choose to meet it is: A) 16. B) 13 1/3. C) 13. Answer: B Diff: 2 Section: 17.2 6) Refer to Scenario 17.1. The lowest level of y* that can be set and still have only the high-productivity people meet it is: A) 16. B) 13 1/3. C) 13. Answer: D Diff: 2 Section: 17.2 7) Refer to Scenario 17.1. If the threshold educational level y is set at 10, A) only individuals in Group A will attain it. B) only individuals in Group B will attain it. C) individuals in both groups will attain it. D) no individuals will attain it. E) some fraction of individuals in each group will attain it. Answer: A Diff: 2 Section: 17.2