**Core Concept**
The clinical presentation of a cerebello-pontine angle (CPA) tumor is primarily due to its location, which affects nearby cranial nerves and structures. The CPA is a critical region where the cerebellum meets the pons, and various cranial nerves, including the trigeminal nerve (CN V), facial nerve (CN VII), and vestibulocochlear nerve (CN VIII), pass through this region.

**Why the Correct Answer is Right**
The correct answer is **Loss of corneal reflex** because the facial nerve (CN VII) is responsible for the corneal reflex. The facial nerve carries sensory fibers from the cornea and motor fibers to the orbicularis oculi muscle. A CPA tumor can compress or damage the facial nerve, leading to a decreased or absent corneal reflex. The corneal reflex is a critical clinical sign, and its loss can indicate a CPA tumor.

**Why Each Wrong Option is Incorrect**
**Option A:** Reduced lacrimation is not typically associated with CPA tumors. Lacrimation is primarily controlled by the autonomic nervous system, and CPA tumors do not directly affect lacrimation.
**Option C:** Hoarseness of voice is not a common early feature of CPA tumors. Hoarseness of voice is more commonly associated with lesions affecting the recurrent laryngeal nerve or the vagus nerve (CN X).
**Option D:** Exaggerated tendon reflexes are not typically associated with CPA tumors. CPA tumors can cause hyporeflexia due to compression of the corticospinal tracts or damage to the spinal cord.

**Clinical Pearl / High-Yield Fact**
A classic clinical sign of a CPA tumor is the "crossed face" sign, which is a weakness of the muscles of one side of the face when the patient attempts to smile. This sign is due to the involvement of the facial nerve (CN VII) in the CPA.

**✓ Correct Answer: B. Loss of corneal reflex**