Final answer:
Participating in the thrift savings plan alters your net pay due to the contributions made which reduce your taxable income. Thus, the option 5 is the correct answer.
Step-by-step explanation:
The benefit at the Department of Energy (DOE) that will alter your net pay amount is participating in the thrift savings plan. This plan is a retirement and savings option which functions similarly to a 401(k) plan. When you contribute to the thrift savings plan, it effectively reduces your taxable income, thereby altering the amount of pay you take home after taxes. This can be categorized under a defined contribution plan, which is a type of retirement plan where the employee, employer, or both make contributions on a regular basis. Other selections such as an alternative work schedule, telecommuting, or using facilities like the child development center or an exercise and wellness facility typically do not affect your net pay in the same direct manner as contributions to retirement savings plans do.