**Core Concept**
The question is testing for a condition associated with a specific type of malnutrition caused by a diet lacking essential nutrients. The patient's symptoms, such as glossitis, diarrhea, and memory loss, point towards a deficiency of a particular vitamin that is crucial for nerve function and mucosal integrity.

**Why the Correct Answer is Right**
The patient's symptoms are consistent with a diagnosis of Pellagra, a disease caused by a deficiency of Niacin (Vitamin B3). Niacin is essential for the synthesis of NAD and NADP, which are crucial for energy metabolism and maintenance of the integrity of mucosal surfaces. The patient's diet consisting only of maize (corn) for many years is likely to be deficient in tryptophan, an amino acid that can be converted into Niacin in the body. The frequent attacks of diarrhea and memory loss are also characteristic features of Pellagra.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the patient's symptoms and history.
**Option B:** While a deficiency of Folate can cause neurological symptoms, it is not directly related to the patient's diet and symptoms.
**Option C:** This option is incorrect as it is not related to the patient's symptoms and history.

**Clinical Pearl / High-Yield Fact**
Pellagra is a classic example of a disease caused by a dietary deficiency of a specific vitamin. It is often referred to as the "four Ds" disease: diarrhea, dermatitis, dementia, and death if left untreated.

**Correct Answer:** C. Pellagra