Which vitamin deficiency is primarily responsible for the development of Angular Cheilitis?

Angular Cheilitis, characterized by the inflammation and cracking at the corners of the mouth, is often linked to a deficiency in certain B vitamins, particularly riboflavin (B2) and sometimes niacin (B3). These vitamins are crucial for maintaining healthy skin and mucous membranes. When there is an inadequate intake of these vitamins, the skin's integrity can be compromised, leading to conditions like Angular Cheilitis.

While vitamin A is important for skin health, its deficiency typically does not directly correlate with Angular Cheilitis. Vitamin C plays a significant role in healing and immune function, but again, it is not the primary vitamin associated with this particular condition. Vitamin D, while critical for overall health, especially bone health, does not have a direct connection to the appearance and symptoms of Angular Cheilitis. Thus, the presence of B vitamin deficiencies directly contributes to the development of this condition, making it the correct answer.