What Is Transmission Control Protocol/Internet Protocol (TCP/IP)

What is transmission control protocol/Internet protocol (TCP/IP) ?

A) software that prevents direct communication between a sending and receiving computer and is used to monitor packets for security reasons
B) a standard that specifies the format of data as well as the rules to be followed during transmission
C) a simple network protocol that allows the transfer of files between two computers on the Internet
D) a standard Internet protocol that provides the technical foundation for the public Internet as well as for large numbers of private networks