Complements and Substitutes in Demand Steps:

• Identify that a fall in laptop prices increases quantity demanded for laptops due to the law of demand.
• Recognize carrying cases for laptops as complements, so their demand rises, pushing up price.
• Note laptops and desktop products are substitutes, so cheaper laptops decrease demand for desktop items.
• Conclude only laptop complements see price increases from higher demand.

Why A is correct:

• Carrying cases for laptops are complements; increased laptop purchases raise demand for cases, increasing their price per the complement goods definition in microeconomics.

Why the others are wrong:

• B: Monitors for desktops are complements to a substitute good (desktops); lower desktop demand decreases monitor prices.
• C: Desktop carrying cases tie to falling desktop demand, lowering their price.
• D: Workstation tables for desktops face reduced demand as substitutes to laptops, decreasing price.

Final answer: A