This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
All are true about pheochromocy except- 
Select and explain. 
A. 90% are malignant, B. 95% occur in the abdomen, C. They secrete catecholamines, D. They arise from symathetic ganlions
A: 90% are malignant
Answer: A: 90% are malignant 
Explanation: 10% malignant ( Harrison 17 pg 2269)