Arrange the following developments in mass communication in chronological…

Concept. A chronological-ordering question in media history is settled by the ERA each medium belongs to, not by a single contested date. Every development below has a range of defensible milestones — first working system, first regular public service, first mass adoption — so the reliable method is to fix the order by the gaps that no choice of milestone can close, and, where two eras run close, by dependency: a medium carried on another medium cannot precede it. The conventional periodisation of mass communication runs: print, then electronic broadcasting (sound before picture), then digital networking, and finally the participatory social platforms built on that network.

Application. Taking the commonly cited milestone for each development gives:

1. Printing press (A) — c. 1440–1455. Johannes Gutenberg’s movable-type press at Mainz produced the first mass-reproduced medium and opens the print era.

2. Radio broadcasting (C) — 1920. Regular public broadcasting began with KDKA, Pittsburgh, on 2 November 1920, followed by the BBC in 1922. Sound broadcasting is the first electronic mass medium.

3. First television network (B) — 1939 to 1946. Network television service dates from NBC’s regular United States service in 1939 and the establishment of the DuMont network in 1946. Picture broadcasting therefore follows sound broadcasting by roughly two decades.

4. Internet (D) — 1969 to 1983. The first ARPANET host-to-host link, in 1969, put the network into operation, and TCP/IP was adopted on 1 January 1983. Public use then spread through the 1990s: the World Wide Web was proposed in 1989 and released publicly in 1991.

5. Social media platforms (E) — 1997 onward. SixDegrees.com (1997) is usually cited as the first social-networking site, and Friendster (2002), MySpace (2003), Facebook (2004) and Twitter (2006) carried the form into mainstream use. These are applications delivered over the internet, so they cannot precede it.

Cross-check. Reading the milestone dates in ascending order confirms the sequence:

How the order is fixed:

• Print, radio and television are separated by decades — the 1440s, 1920 and 1939–1946 are far enough apart that no defensible choice of milestone can reorder them. In particular regular sound broadcasting was already a working mass medium in 1920, about two decades before regular network television service began.

• The internet precedes social media by dependency, not by a date race — social platforms are services carried over the internet, so the network must exist first however each is dated. This step needs the dependency argument precisely because the two run close: the internet’s own public phase (the Web released in 1991, mass adoption through the later 1990s) overlaps the first social-networking sites from 1997.

• Together these settle every adjacent pair — the decade-wide gaps fix the first four positions and the dependency fixes the last, so the sequence is stable whichever milestone convention a source prefers.

Result: the chronological sequence is A, C, B, D, E — printing press, radio broadcasting, first television network, internet, social media platforms.