Which protocol does RMI use to communicate between objects distributed across…

RMI (Remote Method Invocation) enables objects to invoke methods on other objects across a network. It relies on a transport protocol to establish communication between distributed objects. The protocol must support reliable, connection-oriented data transfer to ensure method calls are executed correctly and in order.

Among the listed protocols, TCP/IP is the only one that provides the necessary features for RMI. It ensures data integrity, ordered delivery, and connection management, which are essential for remote method execution.

HTTP is used for web communication and is stateless, making it unsuitable for RMI's persistent object interactions. SMTP is designed for email, and FTP is for file transfers—neither supports the dynamic method invocation required by RMI.

Thus, the protocol used by RMI for distributed communication is TCP/IP.