Most common naturally occurring solid fuel used in villages is __________.

In villages and rural areas, wood is the most commonly used naturally occurring solid fuel for cooking and heating. Option B correctly identifies wood as the primary rural solid fuel. Coal (A) is also used but less commonly in villages due to cost and availability. Paraffin (C) is a liquid fuel, not solid. Coke (D) is a processed coal product, not naturally occurring, and is less commonly used in village settings.