The correct answer is: B. an interactive time-sharing system.
An interactive time-sharing system is a type of computer system that allows multiple users to access the same computer at the same time. Each user has their own terminal, and they can interact with the computer in real time. This type of system is ideal for probability encoding systems because it allows users to enter data and receive results quickly and easily.
An on-line batch system is a type of computer system that processes data in batches. Data is entered into the system and then processed at a later time. This type of system is not ideal for probability encoding systems because it does not allow users to interact with the computer in real time.
A large-scale batch system is a type of computer system that can process large amounts of data. This type of system is not ideal for probability encoding systems because it does not allow users to interact with the computer in real time.
Therefore, the correct answer is: B. an interactive time-sharing system.