Important structures contributing to the esophageal hiatus include the right and left crura and the 

A. endothoracic fascia. 
B. median arcuate ligament. 
C. paraesophageal fat pad. 
D. peritoneum. 
E. phrenoesophageal ligament. 

Answer E

The opening of the diaphragm through which the esophagus passes is known as the esophageal hiatus. The right border is a tendonous portion of the diaphragm known as the right crus which extends along the vertebral body down to the ligament of Treitz. The left border of the hiatus is the diaphragmatic tendon known as the left crus which likewise extends to the vertebral body but is shorter than the right crus. The aorta lies at the base of the esophageal hiatus. The endothoracic fascia ends at the lateral borders of the diaphragm and is not a component of the esophageal hiatus.

There is a variable slip of diaphragm extending from the left crus to the right crus, anterior to the aorta and just superior to the celiac axis. In cadaver dissections, this slip of muscle, known as the median arcuate ligament, cannot always be defined. 

The phrenoesophageal membrane, a fibroelastic ligament arising from the subdiaphragmatic fascia, divides at the lower margin of the esophageal hiatus into a stout, elongated ascending leaf that surrounds the terminal esophagus, and a short descending leaf which merges with the peritoneum on the stomach. Contained within this tent-like structure is the paraesophageal fat pad which marks the gastroesophageal junction.