Answer:
R/2 bps
Explanation:
The TCP protocol is a connection oriented protocol that establishes a three way connection to transfer packets between hosts in a network. It is a protocol in the transport layer of the OSI network model. It is reliable given that all packets dropped are retransmitted.
A bottleneck link is a link of which it's bandwidth continuously reduces to a narrow channel. When two TCP connections are present in a bottleneck, the bandwidth used by the TCP protocol is divided to two halves for both connections, that is R bps/ 2.