The largest freshwater lake among the given options is Wular Lake, option 'A'.

Wular Lake is located in the Indian state of Jammu and Kashmir. It is situated in the Bandipora district and is surrounded by the majestic Himalayan mountain range. Here is a detailed explanation of why Wular Lake is the largest freshwater lake among the given options:

1. Location and Size:
- Wular Lake is located in the Kashmir Valley, between the cities of Srinagar and Bandipora.
- It is spread over an area of approximately 189 square kilometers.
- The lake is situated at an altitude of 1,580 meters above sea level.

2. Hydrology:
- Wular Lake is fed by the Jhelum River, which flows through the valley.
- Several tributaries also contribute to the water supply of the lake.
- The lake acts as a natural flood basin, absorbing excess water during the monsoon season.

3. Biodiversity:
- Wular Lake is home to a diverse range of flora and fauna.
- It serves as an important habitat for several species of migratory birds, including Brahminy ducks, teal, and herons.
- The lake also supports a variety of fish species, making it a significant fishing ground for local communities.

4. Economic Significance:
- The lake has immense economic importance for the region.
- It supports the livelihoods of many fishermen who rely on fishing activities for their income.
- The lake also plays a crucial role in irrigation, providing water for agriculture in the surrounding areas.

5. Environmental Concerns:
- Despite its ecological significance, Wular Lake faces several environmental challenges.
- Factors such as pollution, encroachment, and excessive sedimentation pose threats to the lake's ecosystem.
- Efforts are being made by the government and various organizations to conserve and restore the lake's health.

In conclusion, Wular Lake is the largest freshwater lake among the given options due to its significant size, location, hydrology, biodiversity, economic importance, and environmental concerns associated with it.