This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Studies by Nathaniel Kleitman in 1938 and by Derk-Jan Dijk and Charles Czeisler in the 1990s put human subjects on enforced 28-hour sleep–wake cycles, in constant dim light and with other time cues suppressed, for over a month. Because normal people cannot entrain to a 28-hour day in dim light if at all,[citation needed] this is referred to as a forced desynchrony protocol. Sleep and wake episodes are uncoupled from the endogenous circadian period of about 24.18 hours and researchers are allowed to assess the effects of circadian phase on aspects of sleep and wakefulness including sleep latency and other functions.[page needed]
What time cycle did studies in 1938 and 1990s use on humans?

In 1584, Elizabeth I granted a charter to Sir Walter Raleigh, for whom the state capital is named, for land in present-day North Carolina (then part of the territory of Virginia). It was the second American territory which the English attempted to colonize. Raleigh established two colonies on the coast in the late 1580s, but both failed. The fate of the "Lost Colony" of Roanoke Island remains one of the most widely debated mysteries of American history. Virginia Dare, the first English child to be born in North America, was born on Roanoke Island on August 18, 1587; Dare County is named for her.
Who is the North Carolina state capital named for?

At the same conference, Marshall Sahlins presented a paper entitled, "Notes on the Original Affluent Society", in which he challenged the popular view of hunter-gatherers lives as "solitary, poor, nasty, brutish and short," as Thomas Hobbes had put it in 1651. According to Sahlins, ethnographic data indicated that hunter-gatherers worked far fewer hours and enjoyed more leisure than typical members of industrial society, and they still ate well. Their "affluence" came from the idea that they were satisfied with very little in the material sense. Later, in 1996, Ross Sackett performed two distinct meta-analyses to empirically test Sahlin's view. The first of these studies looked at 102 time-allocation studies, and the second one analyzed 207 energy-expenditure studies. Sackett found that adults in foraging and horticultural societies work, on average, about 6.5 hours a day, where as people in agricultural and industrial societies work on average 8.8 hours a day.
Who called hunter-gathers the original affluent society?