Final answer:
Asymmetry is the most likely ABCDE sign to prompt a patient to seek medical attention for potential melanoma.
Step-by-step explanation:
Melanoma is a type of skin cancer that can develop from melanocytes, which are pigment-producing cells in the skin. Doctors often use the ABCDE mnemonic to aid in the diagnosis of early-stage melanoma. Among the ABCDE signs, the one that is most likely to prompt a patient to seek medical attention is asymmetry. When a mole on the body is asymmetrical, meaning that one half does not match the other half in size, shape, or texture, it may be a warning sign of melanoma.