This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Umblicial cord and diaphragm, Subject name: Anatomy
A congenital diaphragmatic hernia may result from failure of the 
Select and explain. 
A. Septum transversum to develop, B. Pleuroperitoneal membranes to fuse in a normal fashion, C. Pleuropericardial membrane to develop completely, D. Dorsal mesentery of the esophagus to develop
B: Pleuroperitoneal membranes to fuse in a normal fashion
Answer: B: Pleuroperitoneal membranes to fuse in a normal fashion 
Explanation: The formation of the diaphragm occurs through the fusion of tissue from four different sources. The pleuroperitoneal membranes normally fuse with the three other components during week 6 of development. Abnormal development or fusion of one or both of the pleuroperitoneal membranes causes a patent opening between the thorax and abdomen through which abdominal viscera may herniate. fig:- development of diaphragm