**Question 1:** Who did Emma Raducanu face in the Korea Open quarter-final?
**Answer:** Emma Raducanu faced Daria Kasatkina in the Korea Open quarter-final.
**Question 2:** What was the reason for Emma Raducanu's retirement from the match?
**Answer:** Emma Raducanu retired from the match due to a foot injury.
**Question 3:** What is Emma Raducanu's current ranking in British tennis?
**Answer:** Emma Raducanu is currently the British number two in tennis.
**Question 4:** In which tournament did this incident occur?
**Answer:** This incident occurred during the Korea Open.
**Question 5:** What stage of the tournament was Emma Raducanu competing in when she retired?
**Answer:** Emma Raducanu was competing in the quarter-final stage of the tournament when she retired.