Final answer:
An employer is required to pay severance when it's specified within an executed contract between the employee and the employer. The obligation isn't tied to state laws or union membership but to the contractual agreement.
Step-by-step explanation:
An employer must pay severance when there is an executed contract between the employee and the employer in which severance terms were detailed. This means that the requirement to pay severance is not generally dictated by the employer's location (such as right-to-work states) or by the employee's membership in a union, but by the specific terms agreed upon in the employment contract.
In cases where there is no such contract, severance pay may still be offered at the employer's discretion or may be required by company policy, collective bargaining agreements, or as a result of legal actions in response to unlawful termination.
An employer must pay severance when there's an executed contract between the employee and the employer where severance terms were detailed (option D).