TASK DEFINITION: In this task, you're given a context, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both context and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the context or linked information.
PROBLEM: Context: the group originally included lead vocalist Keith Relf Link Information: The Yardbirds are an English blues rock band from London. Formed in May 1963, the group originally included lead vocalist Keith Relf Answer: Robert Plant

SOLUTION: Which person was the lead singer of the Yardbirds the longest?

PROBLEM: Context: He then spent four seasons with the Long Beach Ice Dogs between 1995 and 1999 Link Information: he "Ice Dogs" name and played at the Long Beach Sports Arena. During the team's time in the IHL, it was coached by John Van Boxmeer. Answer: John Van Boxmeer

SOLUTION: Who was John Bryce's head coach while he played for the Long Beach Ice Dogs?

PROBLEM: Context: The Timberwolves were then assigned to British Field Marshal Bernard Montgomery's Anglo-Canadian 21st Army Group under the British I Corps, along with the U.S. 7th Armored Division, in order to clear out the Scheldt Estuary Link Information: I Corps ("First Corps") was an army corps in existence as an active formation in the British Army for most of the 80 years from its creation in the First World War until the end of the Cold War,  Answer: I Corps (United Kingdom)

SOLUTION:
Which allies corps and division size unit that cleared out the Scheldt Estuary was first established?