Which of the Following Best Describes the Unique-Value Effect on Price

Which of the following best describes the unique-value effect on price sensitivity?

A) Customers are less price-sensitive when there are no acceptable substitutes for a product.
B) Customers are less price-sensitive when the purchase is necessary to gain full benefit from assets previously bought.
C) Customers are less price-sensitive when their expenditure for the product or service is a relatively low proportion of their total income.
D) Customers are less price-sensitive in the short run when they cannot store large quantities
Of the product as a hedge against future price increases.