P: Modern medicine has scored significant victories against both, and
Q: It follows that the majority of apparently healthy people are pre-ill.
R: Throughout human history, the leading causes of death have been infection and trauma.
S: These have a long latency period before symptoms appear and a diagnosis is made.
Right Answer is: A
The passage deals with the leading causes of death. Hence R is the opening sentence of the series. R talks about infections and trauma and P tells that modern medicine has scored over both, where both signifies infections and trauma. ‘These’ mentioned in S refers to those diseases referred to in P like arthritis, osteoporosis etc. Thus, S follows P. Thus, the correct sequence is RPSQ. Option A is the correct answer.