**Core Concept**
The carpal bones in the wrist are arranged in two rows: proximal (scaphoid, lunate, triquetrum, and pisiform) and distal (trapezium, trapezoid, capitate, and hamate). The scaphoid bone, being the largest and most mobile, is commonly injured due to its unique anatomy and position.

**Why the Correct Answer is Right**
The commonly injured carpal bone next to the scaphoid is the lunate bone. The lunate bone is situated proximal to the scaphoid in the proximal row of carpal bones. It is subjected to stress and strain due to its position, making it prone to injuries, especially in cases of a scaphoid fracture. The lunate bone is also vulnerable to Kienböck's disease, a condition characterized by avascular necrosis of the lunate bone.

**Why Each Wrong Option is Incorrect**
* **Option A:** The triquetrum is another carpal bone in the proximal row, but it is not as commonly injured as the lunate bone in relation to the scaphoid.
* **Option B:** The pisiform is the smallest carpal bone, and while it can be injured, it is not typically associated with scaphoid fractures or injuries.
* **Option C:** The trapezium is a carpal bone in the distal row, and it is not directly related to the scaphoid or lunate bones.

**Clinical Pearl / High-Yield Fact**
Remember the "SLAC" wrist, which is a common complication of scaphoid fractures: Scapholunate advanced collapse. This condition occurs when the scapholunate ligament is damaged, leading to collapse of the scaphoid and lunate bones.

**Correct Answer: C. Lunate.**