The Family and Medical Leave Act (FMLA) Expressly Exempts "Key

The Family and Medical Leave Act (FMLA) expressly exempts "key personnel" for the general re-instatement requirement. What determines whether or not an employee is considered "key personnel"?

A) The individual has been employed for more than 12 months, and is considered administrative
B) The Individual is at the top 10% of the highest paid employees
C) The individual's role in the business cannot be easily replaced
D) The individual is at the top 5% of longevity in the business