What does a positive cross-price elasticity of demand indicate about two goods?

What does a positive cross-price elasticity of demand indicate about two goods?

• A. They are substitutes; an increase in the price of one raises the quantity demanded of the other.
• B. They are complements; price increase of one raises quantity demanded of the other.
• C. They are unrelated; cross-price elasticity equals zero.
• D. They are substitutes; an increase in price of one lowers quantity demanded of the other.

Answer: (A)