Answer:
The players are acquiring knowledge of a foreign language.
Explanation:
Frankly speaking, even the above is not correct. However, its the right choice, as others are certainly not. The players look like learning a foreign language, accepting they don't have English as their mother tongue. And in that case, this option can be accepted. There is no next level mentioned, nor stats have been shared, not they experience the role-playing. Hence, the above is the correct option.
