Option 1 states that approximately 20% of households in India still use firewood for cooking as per the 2011 Census. This means that out of every 100 households, around 20 use firewood for cooking. However, the correct answer is option 3.

Option 2 states that approximately 40% of households in India use firewood for cooking as per the 2011 Census. This would mean that almost half of the households in the country are still reliant on firewood for their cooking needs. However, this is not the correct answer.

Option 3 states that approximately 50% of households in India still use firewood for cooking as per the 2011 Census. This means that out of every 100 households, around 50 use firewood for cooking. This aligns with the correct answer provided.

Option 4 states that approximately 60% of households in India use firewood for cooking as per the 2011 Census. This would mean that a majority of households in the country still rely on firewood for their cooking needs. However, this is not the correct answer.

In conclusion, option 3 stating that approximately 50% of households in India still use firewood for cooking as per the 2011 Census is the