The answer to this is C. Transparent mode. There are a lot of people who refer to transparent mode as bridge mode. The interfaces all have the same LAN segment. The reason why people use this is they know that they do not have to change their network settings in order to achieve the settings that they want.
The other settings that are available in the choices may be used for other purposes but if the main goal is to reduce the amount of traffic that will be received, transparent mode or TM is going to be the best choice.
When you add a RLC mode, it is likely to cause delays in user traffic. These delays are unavoidable. Hover, the different RLC modes can cause different types of delays. Some can be smaller while other are longer than usual. The transparent mode (TC) causes the least amount of delays.
However, the low latency mode (LC) causes significant delay in user traffic. Likewise, the acknowledged mode (AM) as well as the unacknowledged mode (UM) will cause quite a lot of user traffic delay. Developers recommend using the transparent mode (TC) as it causes the least amount of user traffic delay.