The answer is B. Evolution.
According to the National Cancer Institute, melanoma is one of the most common types of cancer in the United States and the number of cases continues to increase. Melanoma is also the most lethal form of skin cancer and early detection is critical. The ABCDE tool is meant to help educate the public about the appearance and characteristics of common moles, atypical moles, and actual melanomas.
A = Asymmetry (one half does not match the other half)
B = Border (irregular; edges are ragged, notched, or blurred)
C = Color (uneven, shades of black, brown, and tan may be present)
D = Diameter (change in size, usually increasing)
E = Evolving (the mole has changed over the past few weeks or months)