Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[Q]: Protists are thought to be the oldest eukaryotes.
[A]: What is thought to be the oldest eukaryotes?


[Q]: Zinc is active transition metal kind of metal.
[A]: Zinc is what kind of metal.?


[Q]: Aufbau principle gives the order of electron filling in an atom.
[A]:
What gives the order of electron filling in an atom?