This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Which of the following factors determines whether a patient develops acromegaly or gigantism? 
Select and explain. 
A. Sex, B. Age at onset of the tumor, C. Amount of available calcium, D. Degree of function of the tumor
B: Age at onset of the tumor
Answer: B: Age at onset of the tumor 
Explanation: None