**Core Concept**
The Organ of Corti is a critical structure in the mammalian auditory system, responsible for converting sound vibrations into electrical signals that are transmitted to the brain. It is a part of the cochlea, a spiral-shaped structure in the inner ear. The Organ of Corti is composed of specialized sensory cells called hair cells that are embedded in a gel-like substance called the basilar membrane.

**Why the Correct Answer is Right**
The Organ of Corti is situated on the basilar membrane, which is a flexible, sound-sensitive structure that runs along the length of the cochlea. The basilar membrane is lined with the Organ of Corti, which contains hair cells that are embedded in the membrane. When sound waves reach the cochlea, they cause the basilar membrane to vibrate, which in turn causes the hair cells in the Organ of Corti to bend and send electrical signals to the auditory nerve.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the Organ of Corti is not situated on the scala vestibuli, which is one of the three fluid-filled compartments of the cochlea. The scala vestibuli is a separate structure that is responsible for transmitting sound vibrations to the Organ of Corti.

**Option B:** This option is incorrect because the Organ of Corti is not situated on the round window membrane, which is a thin membrane that separates the scala tympani from the middle ear. The round window membrane is not directly involved in the process of sound conversion.

**Option C:** This option is incorrect because the Organ of Corti is not situated on the stria vascularis, which is a layer of epithelial cells that lines the scala media and is responsible for generating the endocochlear potential. While the stria vascularis is an important structure in the cochlea, it is not the location of the Organ of Corti.

**Clinical Pearl / High-Yield Fact**
The Organ of Corti is responsible for detecting sound frequencies in the range of 20-20,000 Hz, and damage to this structure can result in hearing loss or tinnitus (ringing in the ears). Understanding the anatomy and function of the Organ of Corti is critical for diagnosing and treating hearing-related disorders.

**Correct Answer:** C. The Organ of Corti is situated on the basilar membrane.