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: Dental
Breslow's method of histological staging of Malignant Melanoma is: 
Select and explain. 
A. Depth of penetration relation to layers of dermis, B. The vertical distance in mm from granular cell layer to deepest part of melanoma, C. The depth of invasion from stratum. corneum to deepest part of melanoma, D. Width of lesion measured in mm
B: The vertical distance in mm from granular cell layer to deepest part of melanoma
Answer: B: The vertical distance in mm from granular cell layer to deepest part of melanoma 
Explanation: Histopathological staging of malignant melanoma is done by 2 methods:
i) Breslow's method : The vertical distance in mm from granular cell layer to deepest part of melanoma.
ii) Clark method : Depth of penetration is described in relation to different layers of skin.