Read the following statements and re-arrange them

Little
(P) that he had been let down
(Q) stood by all these years
(R) did he realise
(S) by a colleague whom he had

RPSQ

The correct answer is option 4. RPSQ.

Little did he realise that he had been let down by a colleague whom he had stood by all these years.

Let's break down the arrangement "RPSQ":

R: This begins the sentence by indicating a lack of awareness - "Little did he realise."

P: Following "R," this segment describes the realization - "that he had been let down."

S: Next, "S" introduces the background context - "by a colleague whom he had stood by all these years."

Q: Finally, "Q" concludes the sentence by specifying who the colleague is - "whom he had stood by all these years."

So, when arranged as "RPSQ," the sentence flows logically from indicating the lack of awareness to the realization of being let down by a specific colleague.