Question : Which of the following is an assumption made while drawing the demand curve
a:The demand curve must be linear
b:The price of substitutes should not change
c: The quantity demanded should not change
d: The price of the commodity should not change
Option 1: A and B
Option 2: B only
Option 3: A, B and C only
Option 4: A, B, C and D all
Correct Answer: B only
Solution :
Prices of substitutes should not change is the assumption of law of demand.
The assumption behind a demand curve or a supply curve is that no relevant economic factors, other than the product's price, are changing.
Hence only b is the correct answer.