**Core Concept**
Twin foified salt, also known as baking soda (sodium bicarbonate), is a type of antacid and pH regulator commonly used in medical and culinary applications. Its chemical formula is **NaHCO3**, and it plays a crucial role in maintaining acid-base balance in the body.

**Why the Correct Answer is Right**
Sodium bicarbonate works by neutralizing stomach acid, thereby reducing acidity and alleviating symptoms of heartburn and indigestion. It does so by reacting with hydrogen ions (H+) in the stomach to form carbon dioxide (CO2) and water (H2O), which is then expelled from the body as gas. This process helps to maintain a healthy pH balance in the stomach and prevent damage to the esophageal mucosa.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the chemical composition of twin foified salt.
**Option B:** This option is incorrect because it refers to a different type of salt altogether, which is not the correct answer.
**Option C:** This option is incorrect because it is a distractor that does not accurately represent the chemical formula of sodium bicarbonate.

**Clinical Pearl / High-Yield Fact**
Remember that sodium bicarbonate can be used to treat conditions such as metabolic acidosis, where the body's pH levels become too acidic. It is also commonly used as an antacid in the treatment of heartburn and indigestion.

**Correct Answer:** C.