In each of the items there is a sentence of which some parts have been jumbled up. You are required to rearrange these parts which are labelled P, Q, R and S, to produce the correct sentence. Choose the correct sequence and mark in your Answer Sheet accordingly.

For an hour because it had to wait due to dense fog the plane couldn’t take off

P: For an hour · Q: because it had to wait due to dense fog · R: the plane · S: couldn’t take off