Each of the following items in this section consists of a sentence the parts of which have been jumbled. These parts have been labelled P, Q, R and S. Given below each sentence are four sequences namely (a), (b), (c) and (d). You are required to re-arrange the jumbled parts of the sentence and mark your response accordingly.
The doctor `("able to find out")/("P")" "("what had caused")/("Q")" "("the food poisoning")/("R")" "("had not been")/("S")`
The correct sequence should be

Options

A. a) S P R Q
B. b) P R Q S
C. c) P R S Q
D. d) S P Q R