An echocardiogram reveals Charles, an ultramarathon runner, has an enlarged left ventricle. As this increase in ventricular size is supported by increased blood flow and ATP production due to the training Charles has undertaken, this increase in heart size demonstrates

The correct answer would be - physiological hypertrophy.

Explanation:

Physiological hypertrophy of is a condition of the heart that occurs in return of the normal growth an individual such as an athlete like Charles who is a marathon runner in this case.

Left ventricle hypertrophy is a common type of hypertrophy that occurs in this condition in which the left ventricle of the heart increase in size temporary which arises in response to the exercise and function is done by muscles.

thus, the correct answer is - physiological hypertrophy.