In the following items, each passage consists of six sentences. The first sentence (S1) and the final sentence (S6) are given. The middle four sentences in each have been removed and jumbled up. These are labelled P, Q, R and S. You are required to find out the proper sequence of the four sentences and mark accordingly on the Answer Sheet. 

S1: The five-year plans are meant for the nation's economic development. 
P: What are the reasons for it? 
Q: One way of measuring a nation's development is by finding out how much progress there has been in the fight against poverty. 
​R: The reasons are many. 
S: In India, every five-year plan ends with more people coming under the poverty line. 
S6: The most important is, certainly, failure on the family-planning front.