In which part of the stomach are chief cells primarily located?

Chief cells are primarily located in the body of the stomach. These cells are crucial for the secretion of digestive enzymes, particularly pepsinogen, which is the inactive precursor of pepsin. Pepsinogen is later converted to pepsin in the acidic environment of the stomach, allowing it to play an essential role in protein digestion.

The body of the stomach, also known as the corpus, is the main region where the secretion of gastric juices occurs, thanks to the presence of chief cells and parietal cells. The fundus, while it also contains gastric pits and some secretory cells, has a higher proportion of gas exchange and less concentrated secretion. The pylorus is involved mainly in regulating the passage of partially digested food into the small intestine and has fewer chief cells. The antrum largely contributes to mixing food and producing certain hormones, rather than being a major site for enzyme secretion. Therefore, the body is the correct answer as it houses the majority of chief cells necessary for digestion in the stomach.