P: But the achievements of science have not come to man as a ripe apple falls in the lap of a man sitting under an apple tree.
Q: Science is not just the result of observation and experience.
R: It is, on the other hand , the result of centuries of hard work done by man, even at the risk of his own life or health.
S: There is no doubt that science has been the greatest boon to man so far.

A

QRPS

B

SPQR

C

QPRS

D

SQRP