**Core Concept**
The question is testing the concept of enamel structure and the effects of caries on the enamel surface. Enamel is the hardest substance in the human body, composed of highly mineralized, non-living, and non-regenerating structures. Caries on the enamel surface can lead to changes in its appearance and structure.

**Why the Correct Answer is Right**
The correct answer is related to the accentuation of the enamel's surface features, particularly the **amelo-dentinal junction (ADJ)**. When caries affect the enamel, it can lead to the accentuation of the ADJ, also known as the "cervical margin accentuation" or "cervical line accentuation". This occurs due to the demineralization of enamel at the ADJ, causing it to stand out more prominently. This phenomenon is a result of the differential demineralization of enamel and dentin, leading to a more visible boundary between the two.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately describe the effect of caries on the enamel surface. While caries can lead to changes in the enamel's appearance, it is not typically associated with the accentuation of the dentino-enamel junction (DEJ).
* **Option B:** This option is incorrect because it is not a recognized consequence of caries on the enamel surface. The DEJ is not typically affected in the same way as the ADJ in response to caries.
* **Option C:** This option is incorrect because it describes a different anatomical structure altogether. The cemento-enamel junction (CEJ) is the boundary between the cementum and enamel, and is not directly affected by caries on the enamel surface.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that caries on the enamel surface can lead to changes in its appearance, making it more difficult to diagnose. The accentuation of the ADJ can be an indicator of underlying caries, and dentists should be aware of this phenomenon when evaluating patients for caries.

**Correct Answer:** C.