The most important thing about security is to achieve end-to-end security protection of "cloud, pipe, terminal and core". Which of the following does "pipeline" refer to?

The most important thing about security is to achieve end-to-end security protection of "cloud, pipe, terminal and core". Which of the following does "pipeline" refer to?
A . Mobile phones, tablets and other terminals
B . Public cloud or private cloud
C . Chip
D . Wi-Fi/Bluetooth

Answer: D