I don’t know how to explain why this answer is right, so if you do, I would really appreciate your leaving a comment. (I had trouble with at least one other, so I’ll try to get that posted as well.)
Thank you !
In recent years, public libraries in the United States have experienced reductions in their operating funds due to cuts imposed at the federal, state, and local government levels.  However, library staffing has been cut by almost four percent since 2008, and the demand for librarians continues to decrease, even though half of public libraries report that they have an insufficient number of staff to meet their patrons’ needs.
A ) NO CHANGE
B ) Consequently,
C ) Nevertheless,
D ) Previously,
My student’s first impulse was to choose B, which is correct.
He changed his mind because the text mentioned 2008, which is a while ago now. 2008 is previous to 2018. (I may not have his explanation exactly right, but that’s the gist.)
I told him:
- In terms of content, don’t assume that a passage was written recently. This passage could have been written any time since 2008.
- Look at the verbs.
Then I got stuck trying to explain.
Public libraries have experienced reductions . . .
Staffing has been cut . . .
There’s probably some good way to explain that “previously” doesn’t make sense just in terms of logic and semantics, but I’m not coming up with it. So if anyone out there can, I’m eager to hear.
Sticking with the verbs . . . I’m thinking now that a stumbling block, in terms of a high school student grokking this passage, may be the switch to passive voice.
I wonder if my student would have “seen” the logic with the second sentence switched to active:
In recent years, public libraries in the United States have experienced reductions in their operating funds due to cuts imposed at the federal, state, and local government levels. 
However, library staffing has been cutLibraries have cut staff by almost four percent since 2008 . . .
This reminds me of Whimbey’s zoonoses passage, with its non-obvious use of passive voice …. must get that posted.
Actually, I think I’ll give my student this passage tonight, and I’ll try this explanation tomorrow.
UPDATE: Debbie S. says everyone gets this one wrong !