instruction:
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.
question:
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
answer:
Which person was the lead singer of the Yardbirds the longest?

question:
Context: Mouat indicated that the oil was the product of a tree Chaulmoogra odorata, which had been described in 1815 by William Roxburgh, a surgeon and naturalist, while he was cataloging the plants in the East India Company's Link Information: He studied medicine at Edinburgh University and matriculated around 1771 or 1772 Answer: Edinburgh University
answer:
Where was the surgeon and naturalist who described the Chaulmoogra odorata tree in 1815 educated?

question:
Context: Bluesmobile, a battered, decommissioned police car. Link Information: The Bluesmobile is a 1974 Dodge Monaco sedan Answer: Dodge Monaco
answer:
What vehicle model was the Bluesmobile?