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- Calcutta unlike other cities kept its trams.

P- As a result, there is horrendous congestion.

Q-  It was going to be the first in South Asia.

R- They run down the centre of the road.

S- To ease in the city, it was decided to build an underground railway line.

S6- The foundation stone was laid in 1972.