**Core Concept**
The question is testing the knowledge of dermatoglyphics, specifically the most common pattern of fingerprints found in a particular population. Dermatoglyphics is a field of study involving the patterns and ridges present on the skin, particularly fingerprints.

**Why the Correct Answer is Right**
The most common pattern of fingerprints is the **Loftus' loop**. This pattern involves an ulnar loop on the radial side of the finger, which is a characteristic feature of the majority of individuals in the Indian subcontinent. The presence of a well-defined loop on the radial side of the finger is a key identifying feature of this pattern.

**Why Each Wrong Option is Incorrect**
* **Option A:** Arches are the simplest and least common pattern of fingerprints, characterized by a smooth surface without any ridges. This is not the most common pattern.
* **Option B:** Composites are a combination of different patterns, such as a loop and an arch, but they are not the most common pattern.
* **Option C:** Whorls are a type of circular pattern, but they are less common than the **Loftus' loop**.

**Clinical Pearl / High-Yield Fact**
The pattern of fingerprints can be used as an identifying feature in forensic medicine, particularly in cases where other identifying features are not available.

**Correct Answer: A. Loftus' loop**