Answer:
Pancreatic juice, NaHCO₃.
Step-by-step explanation:
The buffers are the chemical solution which neutralizes the acidic effect and the human body also produces the biological buffers which help maintain the pH.
The pancreatic juice secreted by the pancreas gets drained into the duodenum of the small intestine and neutralizes the effect of the acidic content in the stomach bolus. The pancreatic juice contains the sodium bicarbonate which neutralises the effect of the HCl.
Thus, Pancreatic juice, NaHCO₃ is the correct answer.