Explanation:

All of the above.

Gratuity is a defined benefit plan given by the employer to the employee for rendering services continuously for five years or more. It is a monetary benefit usually given at the time of retirement. But there are certain rules that make an employee eligible to receive gratuity before the age of retirement or superannuation. According to the Payment of Gratuity Act, 1972, an employee is eligible to receive gratuity if he has rendered continuous service for at least five years with an organisation. This gratuity is payable to the employee: On his superannuation, or  On his retirement or resignation,