The Organ of Corti is present in

The correct option is scala media.

To understand why this is the correct answer, let us look at the anatomical structure of the mammalian inner ear (cochlea).
The cochlea is a spiral-shaped, fluid-filled structure that is divided into three parallel, fluid-filled canals or ducts: 1. Scala vestibuli: The upper canal, which is filled with perilymph. 2. Scala tympani: The lower canal, which is also filled with perilymph. 3. Scala media: The middle canal (also known as the cochlear duct), which is filled with endolymph.

The Organ of Corti is the sensitive receptor organ for hearing. It contains hair cells that act as auditory sensory receptors.
This organ is located on the basilar membrane, which forms the floor of the scala media. Therefore, the Organ of Corti is physically present inside the scala media.