Which statement correctly distinguishes in-situ remediation from ex-situ remediation, with an appropriate scenario for each?

• A. In-situ remediation treats contaminants in place, such as in-situ bioremediation; ex-situ remediation removes contaminated media for treatment, such as soil washing or excavation and treatment.
• B. In-situ remediation requires excavating soil for treatment, while ex-situ remediation treats contaminants where they are.
• C. In-situ remediation always uses chemical oxidation on excavated soil, while ex-situ only uses bioremediation.
• D. Ex-situ remediation treats contaminants in place, such as chemical oxidation in the soil matrix; in-situ remediation removes contaminated media for treatment elsewhere.

Answer: (A)