Task: Explanation
Input (English): Sebastian Aho (born 17 February 1996) is a Swedish professional ice hockey defenceman who is currently playing under contract as a prospect of the New York Islanders in the National Hockey League (NHL). Aho was drafted by the Islanders, 139th overall, in the 2017 NHL Entry Draft. Question: What was held at the United Center in Chicago, Illinois on June 23-24, 2017 and resulted in Sebastian Aho playing under contract as a prospect of the New York Islanders? Answer: 2017 NHL Entry Draft
Output (English):  Aho was drafted by the Islanders, 139th overall, in the 2017 NHL Entry Draft.