Points to ponder:
Check out carefully for conjunctions that are used in the various answer choice. Also watch out for suitable idioms.

Option A :- INCORRECT
if is a non needed conjunction in this answer choice, over if is an illogical combination and does not follow suit.

Option B :- INCORRECT
about if is another illogical conjunction combo, juxtaposing the two words does not give a clear meaning to what the statement truly means.

Option C :- INCORRECT
A suitable English idiom would be necessary as the right option, but this answer choice lacks it, the idiom dispute-over is preferred over any other.

Option D :- CORRECT
over whether fake hikes should be a first or last recourse correct as dispute-over is correct idiom not dispute about and also whether is preferred when condition is "whether or not".

Option E :- INCORRECT
This option is too wordy and concerning is rather too convectional for this question.