Cross elasticity of demand — practice question

The diagram illustrates a consumer’s demand curve for a product. How does consumer surplus change as the product price falls in $5 increments from $20 to $5?

• AIt increases at a constant rate (%) with each $5 fall.
• BIt increases by a constant amount with each $5 fall.
• CIt increases by a decreasing amount with each $5 fall.
• DIt increases by an increasing amount with each $5 fall.