This is a high-difficulty sentence, but elimination and prediction will help you out a great deal. The first clause and then the road sign “therefore” suggest that the clause with the blanks will provide an alternative to the fact that moving away from fossil fuels is insufficient to stabilize carbon emissions. Blank (ii) has a meaning similar to “store,” so eliminate (F) liberate. (D) incarcerate means to put in prison and refers to people, not substances, so it cannot be correct. (E) capture matches. For blank (i), notice that the technologies must also be for “storing” carbon waste. Choices (B) reduction and (C) diminution can be eliminated. Choice (A) sequestration matches the prediction of “storing” and is correct.