The tax burden will fall most heavily on buyers of the good when the demand curve

is relatively steep, and the supply curve is relative flat

is relatively flat, and the curve is relatively steep

and the supply curve are both relatively flat

and the supply curve are both relatively steep

The answer here is the first option given in the answer choice or is relatively steep, and the supply curve is relative flat.

Explanation:

The tax burden will most likely to fall on the consumers or buyers when the consumer demand for any product or service is relatively inelastic compared to the supply of that particular product or service. A relatively inelastic demand than the supply can be represented or illustrated by a more steeper demand curve compared to the supply curve of the concerned good or service. A relatively inelastic consumer demand basically implies that the consumers are relatively insensitive or unresponsive towards any price change of the concerned good or service in the market. Hence, even if a tax is imposed on the consumers or buyers, the consumer demand for the good or service won't change significantly or much and the government can obtain higher tax revenue in comparison to tax imposition on producers or sellers who are comparatively more responsive or sensitive towards price change of the concerned good or service in the market.