F - information based on opinion is not valid because it has not been proven right
The correct answer is: D. damage to nerves that control the stomach.
The vagus nerve is a cranial nerve that controls stomach contractions and thus, the movement of the food. When the vagus nerve is damaged, the muscles of the stomach do not function properly, so gastroparesis occur. Consequently, food then moves slowly or even totally stops moving through the digestive tract.
In the small intestine, cells contain microvilli, which are tiny hair-like projections that increase nutrient absorption. These projections increase the surface area of the small intestine allowing more area for nutrients to be absorbed.
The answer is c. Electron transport chain