The bioremediation process involving the usage of plants to degrade pollutants is

The correct option is Phytoremediation.

Explanation:
Bioremediation is a biotechnology process that uses living organisms to clean up contaminated environments such as soil, water, and air. Depending on the type of organism utilized, bioremediation can be classified into different categories:

1. Phytoremediation: The prefix "phyto-" comes from the Greek word for plant. Therefore, phytoremediation specifically refers to the use of plants (and their associated microbes) to clean up, degrade, contain, or render harmless environmental contaminants in soil, water, or air. Plants absorb the pollutants and utilize their natural biological processes to break down or stabilize them.
2. Biopile: This is an ex-situ bioremediation technology where excavated contaminated soil is piled into heaps and ventilated to stimulate aerobic microbial activity to degrade pollutants.
3. Composting: This involves mixing contaminated soil with non-hazardous organic materials (like manure or agricultural wastes) to foster the growth of thermophilic microorganisms that degrade the contaminants.
4. Land farming: This is a waste treatment process that is performed in the upper soil zone or in specialized beds where contaminated soils or wastes are mixed with nutrients and tilled to stimulate indigenous microbes to degrade contaminants.

Since the question specifically asks for the process involving the usage of plants to degrade pollutants, Phytoremediation is the correct answer.