Answer:
The argument that supports the idea that Plato created the myth of Atlantis, is that the oldest record of this name is present in Plato's works "Timeu" and "Critias".
Explanation:
You should already know the history of Atlantida. Well, Atlantida is a legendary island that many believe is submerged, or at least that's what the Atlantida myth reveals.
Plato is believed to be the author of this myth, since the oldest records in which Atlantida is cited are in Plato's works, called "Timaeus" and "Critias".
There are several theories as to why Plato created the Atlantida myth. Among these theories, some scholars believe that Plato was inspired by traditions and histories of the past, or that he was inspired by historical facts such as the Trojan War, the eruption of Thera, the invasion of Sicily, among others.