Rearrange the parts of the sentence in correct order.This may be essential atP- where the market fails to deliverQ- swath of an economyR- times, but there is a wide

The given sentence opening is "This may be essential at".We need a word that naturally follows the preposition "at".Part R starts with "times", forming the correct idiomatic phrase "at times" (meaning occasionally or sometimes). Therefore, R must come first.Part R ends with "there is a wide", which requires a noun to follow it. Part Q starts with "swath of an economy", completing the phrase "a wide swath of an economy". Thus, Q follows R.Part P ("where the market fails to deliver") modifies the "swath of an economy", explaining the condition of that sector. Thus, P follows Q.The correct logical sequence is RQP.