Directions: This question consists of a sentence, parts of which have been jumbled. These parts have been labelled as 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 precise details in (P) / allowed historians to (Q) / medieval customaries have (R) / reconstruct since-lost buildings (S)