An industry with a history of systematically funding efforts to

An industry with a history of systematically funding efforts to suppress or discredit research on the harmful effects of its products, the tobacco industry cannot be trusted to research on whether electronic cigarettes lead to cancer.

Understanding the Intended Meaning of the sentence : Tobacco industry is known for its systematical funding to suppress or discredit research on the harmful effects of its products, so it cannot be trusted to fund research on whether electronic cigarettes lead to cancer.

Option A, B and C can be quickly eliminated because as per the intended meaning Tobacco industry is not itself researching instead its funding someone else to research. ALso, research on is an idiomatic usage, so option D is the correct answer.

(A) research on whether electronic cigarettes lead to
'fund' is missing before research. Incorrect.

(B) research on if electronic cigarettes lead to
'fund' is missing before research. Also, the usage of 'whether' is required here. Incorrect.

(C) research into whether electronic cigarettes could potentially lead to
'fund' is missing before research. 'research into' is not idiomatic. The expression 'electronic cigarettes could potentially lead to' is wordy. Incorrect.

(D) fund research on whether electronic cigarettes lead to
Correct.

(E) fund research into the potential of electronic cigarettes for causing
The potential of electronic cigarettes for causing is INCORRECT. It is totally non sensical to talk about the capability or potential of the cigarettes to cause cancer. Usage of 'to cause' is preferred over 'for causing'.

OA should be D.

Thanks.
-Varun