An online gaming company is planning to launch a new game with Amazon DynamoDB as its data store.
The database should be designated to support the following use cases:
* Update scores in real time whenever a player is playing the game.
* Retrieve a player's score details for a specific game session.
A Database Specialist decides to implement a DynamoDB table. Each player has a unique user_id and each game has a unique game_id.
Which choice of keys is recommended for the DynamoDB table?

A. Create a global secondary index with game_id as the partition key
B. Create a global secondary index with user_id as the partition key
C. Create a composite primary key with game_id as the partition key and user_id as the sort key
D. Create a composite primary key with user_id as the partition key and game_id as the sort key