Which districts come under Zone-I of agro-climatic of Bihar?

• A. West Champaran, East Champaran, Gopalganj, Siwan, Madhubani, Begusarai
• B. Supaul, Madhepura, Khagaria, Purnia, Katihar, Kishanganj
• C. Lakhisarai, Jamui, Banka, Munger Bhagalpur
• D. none of the above