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
Pheochromocytoma may be associated with: 
Select and explain. 
A. Medullary carcinoma of the thyroid, B. Papillary carcinoma of the thyroid, C. Anaplastic carcinoma of the thyroid, D. Follicular carcinoma of the thyroid
A: Medullary carcinoma of the thyroid
Answer: A: Medullary carcinoma of the thyroid 
Explanation: Ans. A. Medullary carcinoma of the thyroidMEN 2a: Sipple syndromeMEN 2ba. Thyroid; Medullary thyroid carcinomaa. Thyroid: Medullary thyroid carcinomab. Pheochromocytomab. Pheochromocytomac. Parathyroid hyperplasiac. Mucosal neuromas and Marfanoid appearance