**Core Concept**
Vitamin B2, also known as Riboflavin, plays a crucial role in redox reactions due to its conversion into Flavin Mononucleotide (FMN) and Flavin Adenine Dinucleotide (FAD), which act as electron carriers in various enzymatic reactions. These reactions are vital for energy production, DNA synthesis, and other cellular processes.

**Why the Correct Answer is Right**
Riboflavin is converted into FMN and FAD, which are essential for electron transfer reactions. FAD, in particular, is a crucial component of various dehydrogenases, such as succinate dehydrogenase and NADH dehydrogenase (Complex I), which are involved in the electron transport chain. The redox reactions facilitated by these enzymes ultimately lead to the generation of ATP during oxidative phosphorylation. The presence of FMN and FAD in these enzymes enables the transfer of electrons, thereby facilitating the reduction and oxidation reactions necessary for energy production.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Vitamin C is primarily involved in collagen synthesis, iron absorption, and as a reducing agent in various enzymatic reactions, but it is not directly involved in redox reactions as an electron carrier like Riboflavin.
**Option B:** This option is incorrect because Vitamin E is an antioxidant that protects cells from oxidative damage by scavenging free radicals, but it is not a direct participant in redox reactions like Riboflavin.
**Option C:** This option is incorrect because Vitamin K is essential for blood clotting and bone health, but it is not involved in redox reactions.

**Clinical Pearl / High-Yield Fact**
Riboflavin deficiency can lead to a range of clinical manifestations, including cracks at the corners of the mouth (cheilosis), seborrheic dermatitis, and ocular problems like cataracts and keratitis. It is essential to recognize the importance of Riboflavin in redox reactions and its role in maintaining overall health.

**Correct Answer: C. Vitamin B2 (Riboflavin)**