Here, we take a look at the multiple options with a view to picking the best fit among the array of options available.
In Option A - INCORRECT.
Here, we have a case of plagiarize response to a question raised and expected to be answered in other forms though still retaining its components meaning.
In Option B - INCORRECT.
Here, there's a case of word replacement. The preposition ''by'' is being replaced with a demonstrative pronoun ''that'' which doesn't apply really in the statement for the flow.
In Option C - CORRECT.
Here, the writer is telling us that there's a reservation by a particular group about the subject matter at hand. The component parts of the statement are in agreement with each other and thus makes it the correct option.
In Option D - INCORRECT.
''Concern of'' means the group have a responsibility which they must take care of. It doesn't flow with contextually because they are only raising people's awareness about the petrochemical process.
In Option E - INCORRECT.
Here, there is a proper flow just that the article ''the'' does not add any extra information to the subject matter. Clearly not enough to sway anyone.