Final answer:
For the recycling loop to be successful, it is essential to sort recyclable materials into their respective categories, which allows them to be efficiently processed into new products while preventing contamination and preserving natural resources.
Step-by-step explanation:
To ensure the recycling loop is successful, the required action from the given options is 1) Sorting recyclable materials. Sorting helps to separate recyclables such as aluminum, plastics, glass, and paper products into their respective categories. This process is vital because not all materials are accepted by local recycling authorities, and proper separation ensures that the materials can be efficiently processed into new products. Additionally, sorting prevents the contamination of recyclable materials, which can make them unsuitable for recycling.
Throwing all waste in the same bin, burning waste, and dumping waste in landfills do not contribute to the recycling process. In fact, these methods can release carcinogens into the air, increase smog, and lead to groundwater contamination when toxins from non-biodegradable materials like Styrofoam and plastics accumulate in landfills. Recycling, on the other hand, is a relatively inexpensive solution to environmental contamination and preserves natural resources by reducing the need to extract and process new raw materials.