Answer:
hence option B is correct
Step-by-step explanation:
In the market for jeans, of the following events increases the demand for a pair of jeans, when the prize of the denim falls the operation cost will reduce which will increase the supply not the demand.
The rise in the price of denim skirt( a substitute for jeans) will make the demand of denim skirt fall to which buyers will switch to the substitute of the skirt which is jeans, hence the demand of jeans will rise.
hence option B is correct