The correct answer is option B, sores that do not heal
Reason -
If someone is having a non-healing sore then they must consult the doctor , as there are high probabilities that this person might be having cancer. Generally the sores heal quickly and in case if there persists a sore which is not healing since a long time along with persistent red or white patches in and around the sore, it is advisable to consult a doctor. In some cases, these sores may have arisen due to poor air circulation but it would be advisable to consult a doctor anyhow.