This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
True about metastatic calcification? 
Select and explain. 
A. Serum ca level is normal, B. Occurs in dead/dying tissue, C. Occurs in damaged hea valves, D. Principally affects the kidneys, lungs, and gastric mucosa
D: Principally affects the kidneys, lungs, and gastric mucosa
Answer: D: Principally affects the kidneys, lungs, and gastric mucosa 
Explanation: Metastatic calcification can occur in normal tissues whenever there is hypercalcemia.Metastatic calcification can occur widely throughout the body but principally affects the interstitial tissues of the vasculature, kidneys, lungs, and gastric mucosa. The calcium deposits morphologically resemble those in dystrophic calcification.( Robbins Basic Pathology, 9th edition, page 26 )