**Core Concept**
The classification of dental caries into different classes is based on the location and extent of the enamel and dentin involvement. Class 4 cavities are characterized by their location on the occlusal or occluso-proximal surfaces of molars, involving both the enamel and dentin.

**Why the Correct Answer is Right**
The number of line angles and point angles in a Class 4 cavity is a crucial factor in its classification. Line angles are the angles formed by the intersection of two surfaces, while point angles are the angles formed by the intersection of three or more surfaces. In a Class 4 cavity, there are three line angles and one point angle due to the involvement of the occlusal, occluso-proximal, and proximal surfaces.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because Class 4 cavities involve both enamel and dentin, and typically have more than one point angle.
* **Option B:** This option is incorrect because Class 4 cavities are characterized by their involvement of multiple surfaces, resulting in multiple line angles and point angles.
* **Option C:** This option is incorrect because Class 4 cavities are typically found on the occlusal or occluso-proximal surfaces of molars.

**Clinical Pearl / High-Yield Fact**
To accurately classify caries, it's essential to consider the location and extent of enamel and dentin involvement. This will help in selecting the most appropriate restorative material and technique.

**Correct Answer: C. One point angle and three line angles.**