Concept:Arranging jumbled sentences to form a logical paragraph based on timeline and cause-effect.Explanation:Step 1: S1 says man has progressed. Sentence R starts with "Hitherto", meaning "until now", so it describes man's past backwardness. This follows S1 naturally.Step 2: Sentence Q talks about the present: "Now with scientific knowledge he has done what was impossible". It logically comes after R.Step 3: Sentence S gives a specific achievement: "He has reached the moon". This is an example of the impossible thing mentioned in Q.Step 4: Sentence P looks to the future: "He is on the road to conquer other planets". This leads smoothly to S6 which says what was difficult is now easy.Thus the correct sequence is R Q S P. Option C matches.Answer:C (R Q S P)