Answer:
c) moderators.
Step-by-step explanation:
Since BTC doesn't want to limit employee interaction, but at the same time, it would like to limit what employees can write. The use of moderating features of a discussion forum through the service of a moderator will help them achieve this effectively and efficiently.
A moderator is a neutral individual who has the sole responsibility and skill set to preside and regulate discussions, by ensuring participants do not stray off from the subject matter and the time allotted to them.