S1: History shows that the growth of civilization depends upon the gifts of nature, particularly the wealth yielded by the soil. S6 : In fact, most of the wars in the beginning of humanity’s history were fought for the gain of territory. P : The more land they had, the more they were satisfied. Q : The nature and the quality of the land they possessed were of great importance to them. R : All ancient communities worked hard to produce food. S : There was also a great desire among them to possess as much land as possible. The proper sequence should be
- AR Q S P
- BQ R S P
- CS Q R P
- DP R Q S
Explanation
S1 says civilization depends on the gifts of nature, especially the soil, so R (ancient communities working hard to produce food) is the natural first step. Q follows because it elaborates on the nature and quality of the land they possessed. S extends this into their desire to possess as much land as possible, and P ('the more land they had, the more satisfied') is the consequence of that desire. S6 caps the chain with wars fought for the gain of territory, which only makes sense after P. Hence the order is RQSP, i.e. option A.