They found that people using the sites exhibited "a form of skimming activity", hopping from one source to another and rarely returning to any source they'd already visited.
A.
The site visitors like exhibiting activity.
B.
The site visitors seldom return to any source they’d already visited.
C.
The site visitors have a reading habit that they enjoy staying on the site for hours.
D.
The site visitors like some of the sources but not all of them.