Which area of the stomach directly adjoins the small intestine?

The correct answer is: the pylorus.

Explanation:

The pylorus is the lowest part of the stomach, and is the part that connects with the duodenum, which is the first part of the small intestine. The pylorus and the duodenum connect through the pyloric sphincter, which is a ring of smooth muscle that controls the outflow of the chyme (mass of partly digested food that is formed in the stomach) into the small intestine.