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: Pathology
Malignant change in nevus is characterised by-a)  Darkeningb)  Hemorrhagec)  Itchingd)  Increase in Size 
Select and explain. 
A. ab, B. cd, C. bd, D. ac
B: cd
Answer: B: cd 
Explanation: Warning size of melanoma are : -

Itching or pain in a pre-existing mole.
Enlargement of a pre-existign lesion.
Irregularity of the borders of a pigmented lesion.
Variegation of color within a pigmented lesion.
Assymetry of lesions.