The correct answer is: B. QSRP
The sentence is about a man who realizes that he has been let down by a colleague whom he had stood by all these years. The correct sequence of the words is:
Q: Little did he realize
S: that he had been let down
R: by a colleague whom he had
P: stood by all these years
The word “little” indicates that the man did not expect to be let down. The word “realize” indicates that he came to understand something that he had not previously known. The word “let down” indicates that the man was disappointed or betrayed. The word “colleague” indicates that the man was betrayed by someone he worked with. The word “stood by” indicates that the man had been loyal to his colleague.
The other options are incorrect because they do not make sense in the context of the sentence. For example, option A (QSPR) would mean that the man realized that he had been let down by a colleague whom he had stood by all these years, but then he stood by the colleague again. This does not make sense, because if the man had realized that he had been let down, he would not have stood by the colleague again.