Concept:Logical sequencing of sentences based on coherence and flow of ideas.
Explanation:S1 states that India has the largest youth population in the world.
Sentence Q follows logically by describing youth as the most dynamic and vibrant segment, which builds directly on S1.
Sentence R then explains that to optimally tap their constructive energy, the Department of Youth Affairs pursues personality development and nation building.
Sentence P adds that the Department has also recognised adolescents as an important segment, aligning with the aims mentioned in R.
Sentence S details the supportive role of other Ministries and State Governments, leading naturally to S6 which describes the Department as a facilitator and catalytic agent.
Any other sequence disrupts this logical flow. For example, starting with P or R would be too specific without first establishing the importance of youth as done in Q.
Thus the correct order of the middle sentences is Q, R, P, S.
Answer:Option B (QRPS)