Concept:The correct sequence must maintain a logical flow from the introduction of Gaganyaan to its long-term impact, with each sentence building on the previous one.
Explanation:S1 introduces Gaganyaan as a national programme.
Sentence Q states that the Gaganyaan Programme marks an inflection point in India's space growth, which directly follows S1.
Sentence P then describes the creation of a new vertical within ISRO to steer this growth, logically after Q.
Sentence R explains the role of this new vertical, which includes demonstrating human space flight to Low Earth Orbit in the short term.
Sentence S introduces the new ISRO centre (Human Spaceflight Centre) formed for Low Earth Orbit flights, supporting the activities described in R.
Thus, the sequence Q-P-R-S preserves the progression from significance to structural change to specific goals.
Other options (QSRP, RSPQ, SPRQ) disrupt this logical order by placing details before context or mixing cause and effect.
Answer:QPRS