What are the name of the salts formed by ethers?

The correct answer is option 1. Oxonium salts.

Oxonium salts are produced when ethers reacts with mineral acids (like HCl, H₂SO₄, etc.). In ethers due to the presence of lone pairs of electron on the oxygen atom, it behaves as a Lewis base and reacts with a strong acid to form protonated oxonium salts. Since, the oxygen atom donates the lone pair of electrons so, the ether is said to be basic in nature.