(1) Simplex: Simplex communication is unidirectional, meaning data can only flow in one direction at a time (e.g., radio broadcast). This is not how mobile phone communication works.
(2) Half-Duplex: Half-duplex communication allows data to flow in both directions, but only one direction at a time (e.g., walkie-talkie). You can either transmit or receive, but not simultaneously. This is not how mobile phone communication works.
(3) Full-Duplex: Full-duplex communication allows data to flow in both directions simultaneously (e.g., telephone conversation). Both parties can talk and listen at the same time. This is how mobile phone communication works.
(4) Double-Duplex: The term "Double-Duplex" is not a standard term in communication modes. It's not a recognized mode of communication.
Therefore, the communication over a mobile phone is an example of (3) Full-Duplex.
Column-I has statements made by Shanthala; and, Column-II has responses given by Kanishk.