is a fluid similar to cerebrospinal fluid that fills the space between the bony labyrinth and the membranous labyrinth.

Perilymph is a fluid similar to cerebrospinal fluid that fills the space between the bony labyrinth and the membranous labyrinth.

Explanation:

The inner ear consists of the bony labyrinth and the membranous labyrinth, it is filled of endophilia and surrounded by perinfilia (the bony labyrinth surrounds the membranous, between both there is a space occupied by the perilymph). Perilymph is an albuminous fluid that has an ionic composition similar to the extracellular environment, it bathes the tympanic and vestibular ramps, fully occupying the bony cavities of the inner ear, bathing the membranous parts located inside these cavities.

i believe the answer is c