Some parts of a sentence have been jumbled up, and labelled P, Q, R and S. Select the option that gives the correct sequence in which these parts can be rearranged to form a meaningful and grammatically correct sentence.
The dualism characteristic of medieval serfdom,
P. may be traced all through
Q. its formation out of debased
R. freedom and rising servitude,
S. the history of the
middle ages.
