1. Well developped offspring, and portable baby food despencing. Mamalian young are generally quite well developed when they are born, and the parent does not need to find any specific types of food for the new born since the mother already provides te perfect nutrition.
2. Internal heating allows mammals to remain quick and active in cold climates.
3. Fur is really effective and cheap to produce.
Answer:
genetics;the study of heredity and the variation of inherited characteristics.
evolution;evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection
variation;a change or difference in condition, amount, or level, typically with certain limits
Explanation:
The answer to your question is A)front
