Economists can’t conceive of any resource or product for which the: (i) Price elasticity of demand is zero (0) and the demand curve is vertical. (ii) Price elasticity of supply is zero (0) and supply curve is vertical. (iii) Income elasticity of demand is negative. (iv) Supply curve is perfectly horizontal. (v) Opportunity costs are zero (0) and hence this is a "free good".
Please someone suggest me the right answer.