The esophagus has a simple but significant functions to animals who has it. These functions can be a) to swallow food and serve as a passageway to the stomach and b) may serve to release the eaten food that might have some harmful compositions or chemicals -the vomit response.
I believe it is D. More African elephants today naturally lack tusks compared to the elephant populations 100 years ago, because big game hunters sought elephants for ivory.
Taking a measure of someones blood glucose level before they eat in the morning is a measure of fasting blood glucose. A normal measure of fasting blood glucose is 3.8 to 5.5 mmol. If the value were higher, say 5.8 mmol then the patient would be described as being pre-diabetic. Since the value is the highest in the range of being normal she should be monitored for pre- diabetes.