kunalm
Because of recent seismic activity all along the Bleisner fault in the northern Pacific,
environmental groups are concerned by offshore oil drilling and mineral exploration taking place in the immediate vicinity might exacerbate an already volatile situation.
1. "environmental groups" vs "a concern"C)
a concern by environmental groups is that the offshore oil drilling and mineral exploring taking place
D)
a concern of the environmental groups is the offshore oil drilling and mineral exploring taking place
Because ... , is a subordinator modifying the action (Why are they concerned? Because of ...)
The action should be done by "environmental groups," not "a concern"
2. "concerned by" vs "concerned that"A) environmental groups are concerned
by offshore oil drilling and mineral exploration taking place
B) environmental groups are concerned
that offshore oil drilling and mineral exploration taking place
E) environmental groups are concerned
by the offshore oil drilling and mineral exploring taking place
Looking past the part underlined, we have "in the immediate vicinity might
exacerbate an already volatile situation."
So we have another action being done, thus we need to use "that" as a conjunction. Using the preposition "by" doesn't do anything to fix the issue.