**Core Concept**
The patient's difficulty reading the newspaper is likely due to a problem with the extraocular muscles, which control eye movement and alignment. This condition affects the patient's ability to converge his eyes, leading to blurred vision.

**Why the Correct Answer is Right**
The patient's symptoms suggest a problem with the medial rectus muscle, which is responsible for eye adduction (converging the eyes). When the medial rectus muscle is unable to contract properly, the patient experiences difficulty focusing on near objects, leading to blurred vision. This condition is often due to a congenital or acquired palsy of the oculomotor nerve (cranial nerve III), which innervates the medial rectus muscle.

**Why Each Wrong Option is Incorrect**
**Option A:** The superior rectus muscle is responsible for eye elevation, not convergence. A palsy of the superior rectus muscle would cause difficulty looking upward, not reading the newspaper.
**Option B:** The inferior oblique muscle is responsible for eye rotation and elevation, not convergence. A palsy of the inferior oblique muscle would cause difficulty looking upward and outward, not reading the newspaper.
**Option C:** The lateral rectus muscle is responsible for eye abduction (moving the eye away from the midline), not convergence. A palsy of the lateral rectus muscle would cause difficulty looking outward, not reading the newspaper.

**Clinical Pearl / High-Yield Fact**
The patient's symptoms are classic for a sixth cranial nerve palsy, which affects the oculomotor nerve. This condition can be caused by a variety of factors, including trauma, aneurysms, and tumors.

**Correct Answer:** C. lateral rectus