Detailed Instructions: In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.
Q: Question: In the ear of mammals:
Options: <0> The sterocilies of the hair cells contact the basilar membrane. <1> The tympanic ramp contains endolymph. <2> The basilar membrane is wider and more flexible at the level of the helicotrema. <3> The sensory cells are those of Deiter. <4> The oval membrane has a larger surface than the tympanic membrane.
A:
biology