To determine which characteristic of an animal species would make it a good candidate for domestication as a companion animal, we can evaluate the options provided:
1. **Aggressiveness:** Animals that are aggressive would generally not be good candidates for domestication as companion animals because they could pose a threat to humans or other animals in a household. Therefore, aggressiveness is not a desirable characteristic in a companion animal.
2. **Good social qualities:** Animals with good social qualities, such as being friendly, sociable, and forming bonds with humans, are excellent candidates for domestication as companion animals. These qualities make it easier for the animal to interact positively with humans and integrate into a household.
3. **Complex feeding requirements:** Animals with complex feeding requirements may not be the most practical choice for domestication as companion animals. It could be challenging for owners to meet these needs consistently, affecting the well-being of the animal. Therefore, simple and manageable feeding requirements are more favorable.
4. **Coming from an exotic environment:** Animals coming from exotic environments may have specific needs that are difficult to meet in a domestic setting. The environmental conditions they are accustomed to might not be replicable in a home environment, making it challenging to provide proper care.
Therefore, among the given options, animals with good social qualities are the most suitable candidates for domestication as companion animals. Their ability to bond with humans and display positive social behaviors makes them well-suited for living in close proximity with people and being part of a household.
