Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

[Q]: Diamphidia nigroornata or Bushman arrow-poison beetle, is an African leaf beetle species in the genus Diamphidia.
[A]: Is Diamphidia nigroornata a genus or species?


[Q]: In the 1950s, a family that owned a farm near Beulah, Michigan kept a bull chained to an elm . The bull paced around the tree, dragging the heavy iron chain, which led to a groove in the bark . The groove deepened over the years. Though for whatever reason, it did not kill the tree. After some years, the family took their bull away. They cut the chain, leaving the loop around the tree and one link hanging down. Then one year, agricultural disaster struck Michigan in the form of Dutch Elm Disease. All of the elms lining the road leading to the farm became infected and died. Everyone thought that the old elm would be the next. The farm owners considered doing the safe thing: pulling it out and cutting it up into firewood before it died. But they simply could not bring themselves to do it. It was as if the old tree had become a family friend. So they decided to let nature take its course. Amazingly, the tree did not die. Nobody could understand why it was the only elm still standing in the county! Plant experts from Michigan State University came out to observe the tree. They observed the scar left by the iron chain, now almost completely covered by bark. The experts decided that it was the chain that saved the elm's life. They reasoned that the tree must have absorbed so much iron from the chain that it became immune to the virus. It's said that what doesn't kill you will make you stronger. Or, as Earnest Hemingway put it, "Life breaks us all, but afterwards, many of us are strongest at the broken places."
[A]: What actually saved the elm?


[Q]: It is well known that autonomic failure is severer in patients with dementia with Lewy bodies (DLB) compared with patients with Parkinson's disease (PD). According to the Braak's hypothesis, Lewy bodies first appear in the olfactory bulb or peripheral autonomic nervous system. Lewy bodies in the peripheral autonomic nervous system ascend to dorsal motor nuclei of vagus nerve, while those in the olfactory bulb expand to the limbic system. Lewy bodies later attain the substantia nigra. However, it seems that Braak staging can not explain difference in severity of autonomic failure between DLB and PD. As a possibility, in DLB patients with significant autonomic failure, Lewy bodies may have been localized to the peripheral autonomic nervous system in a long time before onset of dementia or parkinsonism, and propagation of Lewy bodies into the central nervous system may be initiated by apparition of certain promotion factor, such as ageing and amyloid-.
[A]:
Which disease of the central nervous system is characterized by the presence of Lewy bodies?