Answer:
D: the squeezing of food through the intestines.
Step-by-step explanation:
A physical change is a change that alters the form or appearance of a substance but does not change its chemical composition. In the process of digestion, a physical change that occurs is the squeezing of food through the intestines. This is a mechanical process in which the walls of the intestines contract and relax to push the food through the digestive tract.
The other options listed in the question are not examples of physical changes that occur during digestion. The breakdown of food substances by digestive juices is a chemical process, in which enzymes in the digestive juices break down the food into smaller molecules. The addition of acids to create a ball of food and the secretion of pepsin to change proteins to peptides are both chemical reactions that occur during digestion.
Therefore, the correct answer is option D: the squeezing of food through the intestines.