In this section, each item consists of six sentences of a passage. The first and sixth sentences are marked as S1 and S6. The middle four sentences in each have been jumbled up and labelled as P, Q, R and S. This is followed by four options each suggesting a sequence of the sentences. Identify the most appropriate option. S1: In agriculture, water is mainly used for irrigation. S6: Hence, it is difficult to practice agriculture without assured irrigation during dry seasons. P: The large tracts of the country are deficient in rainfall and are drought prone. Q: Winter and summer seasons are more or less dry in most part of the country. R: Irrigation is needed because of spatio-temporal variability in rainfall in the country. S: North-Western India and Deccan Plateau constitute such areas. The correct sequence should be