Teacher:Generate a correct and concise answer for the question based on the words in the context.
Teacher: Now, understand the problem? Solve this instance: Context : 45 Commando Royal Marines (pronounced ''four-five commando'') is a battalion sized unit of the British Royal Marines and subordinate unit within 3 Commando Brigade Royal Marines, the principal Commando formation, under the Operational Command of Commander in Chief Fleet.
Question : What military organization did 45 Commando belong to?
Student:
Royal Marines