What process involves using a machine to pull plugs out of the soil to reintroduce oxygen?

Core aeration is the correct answer because it is a specific technique designed to enhance soil health by addressing compaction. During this process, a machine removes small cylindrical plugs of soil from the lawn, which helps to alleviate compaction and allows for better air exchange within the soil structure. This improved airflow is essential for root growth and overall plant health because it enables soil microorganisms to thrive, which in turn promotes nutrient availability.

In addition to providing oxygen, core aeration facilitates water absorption and enhances the movement of essential nutrients into the root zone. By disrupting the compacted layers in the soil and creating channels, it encourages deeper root growth and improves overall turf resilience.

The other choices do not pertain specifically to the process of pulling plugs from the soil for aeration purposes. For instance, soil compaction refers to the densification of soil particles, which can actually hinder oxygen flow rather than enhance it. Dethatching involves the removal of a layer of organic matter that forms between the soil surface and the grass blades, which is a different maintenance practice. Soil conditioning refers to the process of improving soil structure and fertility, but it does not specifically involve the mechanical extraction of soil plugs like core aeration does.