Explanation:

Option (4) is correct.
Explanation: Factors Determining Elasticity of Demand
(i) Objective Factors:
(a) Nature of commodity,
(b) Existence of substitutes,
(c) Alternative uses of a commodity,
(d) Postponement of consumption, and
(e) Joint demand.
(ii) Subjective Factors :
(a) Habits of consumers,
(b) Change in income of consumers,
(c) Standard of living of people,
(d) Share in total expenditure, and
(e) Class of buyers.
(iii) Social Factors :
(a) Distribution of National Income, and
(b) Rationing System.
(iv) Price Factors :
(a) General price level, and
(b) Effect of time element.