To solve this problem, we need to identify what succus entericus refers to. Let's analyze each option:$\newline \bullet$Option 1: Pancreatic juice - This is the digestive fluid secreted by the pancreas, containing enzymes like trypsin, amylase, and lipase. It is not referred to as succus entericus.$\newline \bullet$Option 2: Intestinal juice - This is the correct answer. Succus entericus is the term used for the intestinal juice secreted by the glands in the walls of the small intestine. It contains enzymes that aid in the final stages of digestion.$\newline \bullet$Option 3: Gastric juice - This is the digestive fluid produced by the stomach, containing hydrochloric acid and pepsin. It is not referred to as succus entericus.$\newline \bullet$Option 4: Chyme - This is the semi-fluid mass of partly digested food that is expelled by the stomach into the duodenum. It is not referred to as succus entericus.$\newline$Therefore, the correct option is Option 2: Intestinal juice.