The ans is B

This pt has mesenteric ischemia (probably due to severe atherosclerosis). This means that the GI will not get adequate blood supply which can be very painful after meals since that is when the blood supply demand is the highest. Pts lose weight because the avoid eating due to the intensity of the pain.

This is the same patho-phys behind a stable angina. Due to narrowing of the lumen there is diminished blood supply to the heart. The pain increases when blood and oxygen demand increases.