In each question one sentence is given. In each sentence certain words are in bold and numbered from A to E. Below the sentences are given five options with possible pairs of interchange of those bold words. Choose the pair(s) of words which are needed to be interchanged to make the sentence grammatically correct and meaningful.

When I (A)switched on the fan, it (B)started to (C)rotate but (D) power stopped because of (E) suddenly failure.