The roof of scala media is called :

The correct option is A Reissner's membrane
Scala media is the space within cochlea called scala media is filled with endolymph. The middle chamber is called scala media. It is actually the cochlear duct and is an outgrowth from the saccule. Therefore, it is filled with endolymph, which is secreted by its epithelium lining.

The roof of scala media is called Reissner’s membrane. Reissner's membrane (vestibular membrane) is a membrane inside the cochlea of the inner ear. It separates scala media from scala vestibuli. Together with the basilar membrane, it creates a compartment in the cochlea filled with endolymph, which is important for the function of the organ of Corti. It functions as a diffusion barrier, allowing nutrients to travel from the perilymph to the endolymph of the membranous labyrinth.