The formation of peroxide linkage in ether due to the exposure in air can be detected by treating it with

The formation of peroxide linkage in ether due to the exposure in air can be detected by treating it with aqueous ferrous ammonium sulphate followed by the addition of ammonium thiocynate.

Ammonium thiocyanate is utilised in the production of rustproofing compounds, thiourea, transparent artificial resins, herbicides, matches, textile dyeing and printing adjuvants, tracers in oil fields, and the separation of zirconium and hafnium from textiles.

Hence, correct option is c.