Final answer:
The three bulges on the incisal edge of a newly erupted central incisor, known as mammelons, are not accurately described by any of the answer options provided. The closest option is ridges, but this term is generally used to describe elongated projections on the chewing surfaces of molars and premolars.
Step-by-step explanation:
These are rounded protuberances that can be found on the incisal edges of the newly erupted permanent incisors. They typically wear away after a while as the tooth is used for biting and comes into contact with other teeth. Mamelons are not mentioned in the answer options provided, but if we consider the options available (cusps, fossae, margins, ridges), none seem to specifically describe these bulges; rather, they describe other parts or features of teeth. Therefore, with the provided options, none of them accurately describes mammelons. However, if we have to choose from them, ridges are the closest, as they are elevated areas like mammelons, but ridges generally refer to elongated projections on the chewing surfaces of molars and premolars, not the incisal edges of incisors.