Introduction:
Among the given sewage treatment options, the option that requires the largest land requirements for a given discharge is the oxidation pond.

Explanation:

1. Trickling Filter:
- A trickling filter is a biological wastewater treatment process that uses a bed of rocks or other media to support microbial growth.
- The wastewater is distributed over the filter media, and as it trickles through the media, the organic matter is removed by the microorganisms.
- Trickling filters are known for their compact design and ability to treat high volumes of wastewater in a small area.
- They require less land compared to other treatment options.

2. Anaerobic Pond:
- An anaerobic pond is a type of wastewater treatment system that utilizes anaerobic bacteria to break down organic matter in the absence of oxygen.
- The pond is designed to be sealed at the bottom to prevent oxygen from entering, creating an anaerobic environment.
- Anaerobic ponds are typically used for the treatment of high-strength industrial wastewater.
- These ponds generally require less land compared to aerobic treatment options like oxidation ponds.

3. Oxidation Ditch:
- An oxidation ditch is an extended aeration wastewater treatment process that combines elements of both activated sludge and oxidation ponds.
- It consists of a long, narrow channel with mechanical aerators that provide oxygen to the wastewater.
- The wastewater is circulated and mixed with the help of mechanical devices.
- An oxidation ditch requires moderate land requirements compared to other treatment options.

4. Oxidation Pond:
- An oxidation pond, also known as a stabilization pond or lagoon, is a large, shallow body of water designed for the treatment of wastewater.
- It relies on natural processes, including sunlight, algae, and aerobic bacteria, to break down and treat the organic matter in the wastewater.
- Oxidation ponds require a significant amount of land as they need to be large enough to accommodate the wastewater volume and provide adequate retention time for treatment.
- The size of the oxidation pond depends on factors such as the wastewater flow rate, organic load, and treatment objectives.
- Due to their extensive land requirements, oxidation ponds are typically used in rural areas where land availability is not a constraint.

Conclusion:
Among the given sewage treatment options, the oxidation pond requires the largest land requirements for a given discharge. This is because oxidation ponds rely on natural processes and require a significant amount of land to accommodate the wastewater volume and provide adequate retention time for treatment.

Oxidation pond - Standing pond with minimum depth, so the sunlight can penetrate into the tank for photosynthesis at the bottom of the tank and provide oxygen for aerobic oxidation. For less depth, more surface area and large detention time is required.