**Core Concept**
Otosclerosis is a type of bone dysplasia affecting the middle ear, leading to fixation of the stapes bone and conductive hearing loss. The condition can cause tinnitus due to abnormal sound transmission and altered auditory processing.

**Why the Correct Answer is Right**
Tinnitus in otosclerosis is primarily caused by the abnormal transmission of sound vibrations to the inner ear. The fixation of the stapes bone disrupts the normal conduction of sound waves, leading to an abnormal perception of sound. This results in the sensation of tinnitus, which can range from a mild ringing to a loud, debilitating noise.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because otosclerosis primarily affects the middle ear bones, not the cochlea or auditory nerve, which are more commonly associated with tinnitus in other conditions.

**Option B:** This option is incorrect because while some cases of otosclerosis may be associated with autoimmune disorders, the primary cause of tinnitus in otosclerosis is the abnormal transmission of sound vibrations.

**Option C:** This option is incorrect because tinnitus in otosclerosis is not primarily due to the effects of loud noise exposure, which can cause permanent damage to the hair cells in the cochlea.

**Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that otosclerosis often presents with a characteristic "tone" or "sound" in the ear, which can be a key diagnostic clue. This sound is often described as a ringing or hissing noise and can be a key distinguishing feature from other causes of tinnitus.

**Correct Answer: C.**