The diagram below shows a stack of rock layers. These layers have not changed position since they formed. Examine the diagram and answer the question that follows. If the age of Layer 4 is 400 million years and the age of Layer 1 is 500 million years, then the age of Layer 3 is A. older than 500 million years. B. between 400 million and 500 million years. C. 500 million years. D. younger than 400 million years.

the abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. the region occupied by the abdomen is termed the abdominal cavity. the stomach secretes acid and enzymes that digest food. ridges of muscle tissue called rugae line the stomach. the stomach muscles contract periodically, churning food to enhance digestion. the pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.