Answer:
The correct answer is letter "A": relatively more elastic in market X than market Y.
Explanation:
Third-degree price discrimination refers to offering a good or service at different prices in different places. Demand elasticity describes the responsiveness in price change of a good or service because of changes in other factors within the same market.
Thus, if a pure monopoly offers its products at a higher price in "X" market than "Y" market, it is likely the case that elasticity is higher in "X" market compared to "Y" market.