Final answer:
If a Migrant Domestic Worker (MDW) is missing, the employer should contact the Ministry of Manpower (MOM) within 24 hours of the disappearance to ensure legal compliance and the worker's safety.
Step-by-step explanation:
When a Migrant Domestic Worker (MDW) goes missing, the employer must contact the Ministry of Manpower (MOM) as soon as possible. The correct answer to the question is a) Within 24 hours of disappearance. This prompt response is important not only for the safety of the MDW but also to adhere to the legal requirements and responsibilities as an employer. In situations such as this, timely action is essential, and waiting too long could have serious repercussions.