Direction: The following passage consists of six sentences. The first and the sixth sentences are given. The middle four sentences in each have been removed and jumbled up. These are labelled P, Q, R and S. You are required to find out the proper sequence of the four sentences and choose the correct order from the options.

S1: Palaeobotany is the study of fossil plants preserved in rocks dating back in millions of years.
 

P : Records of the history of the world are contained in fossils.
 

Q : Through the ages, plants have evolved from simple to more complex forms.
 

R : First there were water plants then land plants appeared during the Paleozoic era.
 

S : But since the fossil remains appear locked in rock layers, they are closely related to the geologist area of investigation.
 

S6: The fossil plants indicate the age of the rock, and also point to facts regarding climate, temperature and topography.