Final answer:
A keratoma is another term for a callus, which is a thickened area of skin typically forming from repeated friction or pressure.
Step-by-step explanation:
The term keratoma is another name for a callus. A callus is a thickening of the skin which usually forms on the hands or feet due to repeated friction or pressure. This is different from a wart, which is caused by a virus, and a tumor, which is an abnormal growth of tissue that can be benign or malignant. A birthmark, on the other hand, is a mark on the skin formed before birth and is not related to thickening of the skin like a keratoma. Therefore, the correct answer to the question 'Which of the following terms is another name for a keratoma?' is 'b) callus'.