Explanation:

- Option 1: Mizoram

- Mizoram is a state in Northeast India known for its peaceful electoral processes.

- However, in 2020, it did not receive the National Award for Best Electoral Practices.

- Option 2: Meghalaya

- Meghalaya, another state in Northeast India, is known for its unique cultural practices.

- It was not the recipient of the National Award for Best Electoral Practices in 2020.

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- Option 3: Kerala

- Kerala is a state in South India with a high literacy rate.

- It was awarded the National Award for Best Electoral Practices in 2020.

- Option 4: Karnataka

- Karnataka is a state in Southern India.

- While it has excellent governance practices, it did not win the 2020 award.

The correct answer is Option 3: Kerala.