This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Which of the following pa of the colon has maximum basic electrical rhythm (BER)? 
Select and explain. 
A. Ascending colon, B. Descending colon, C. Sigmoid colon, D. Transverse colon
C: Sigmoid colon
Answer: C: Sigmoid colon 
Explanation: Basic electrical rhythm (BER) is initiated by the interstitial cells of Cajal, stellate mesenchymal pacemaker cells. The rate of the BER is about 4/min in the stomach. It is about 12/min in the duodenum and falls to about 8/min in the distal ileum. In the colon, the BER rate rises from about 2/min at the cecum to about 6/min at the sigmoid. The function of the BER is to coordinate peristaltic and other motor activity, such as setting the rhythm of segmentation; contractions can occur only during the depolarizing pa of the waves. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. (2012). Chapter 27. Gastrointestinal Motility. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks (Eds), Ganong's Review of Medical Physiology, 24e.