Instructions: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
Input: [header] How to detect symptoms of avascular necrosis [title] Know that stabbing, shooting pain is the only major symptom. [step] As the bone or joint is breaking down, it will manifest as sharp pains that are often described as stabbing, shooting, tearing or piercing. If you have avn in your hip, this pain will be more focused in the groin, thigh and buttocks. <sep> (A) [substeps] This signals an increased risk of the avn to occur later in the process of diagnosis. Abdominal pain and pressure may also be observed. (B) [substeps] It is easy to detect the symptoms of having avn as it has only one: pain. Unfortunately, avn is painless at first, so if you experience pain, it means that avn is getting worse. (C) Severe avn is especially painful to the naked eye, and recovery from avn before you begin treatment is slow. If you roll over under gravity, the pain is more severe. (D) [title] Pay attention to blood loss in the area following the stab. [step] Blood leaks from the wound and the bleeding does not stop after a significant amount of blood has soaked into the thigh.
Output:
B