Which subterranean reproductives are mainly responsible for egg production?

The term "subterranean reproductives" typically refers to specific roles in the reproductive structure of certain social insects, such as termites. In this context, the correct answer, which identifies the responsibility for egg production, pertains to supplementary reproductives.

Supplementary reproductives are individuals in a colony that can assist the primary reproductives with reproductive tasks, particularly in larger colonies. This can include laying eggs when the primary reproductives (the king and queen) are unable to do so, or when there's a need for increased egg production to support the growth of the colony. Their presence ensures that the colony can maintain a steady population and adapt to changes in environmental conditions or social structure.

Primary reproductives are crucial for a colony because they are the main egg producers. However, their capacity for reproduction can sometimes be hindered by various factors such as health or environmental stress. In such scenarios, supplementary reproductives can step in to fulfill the colony's needs for reproduction.

Secondary and tertiary reproductives generally play roles that are not primarily focused on egg production, which is why they do not fit the context of the question regarding which subterranean reproductives are mainly responsible for this function.