The correct option is
A P S Q R
The first statement in the sequence should be the one that best connects with S1. It should be a continuation or extension of S1.
P is first in the sequence: S1 says that progress and success are attained in slow degrees. P goes on to says that, despite this fact, slow progress make us grow impatient.
P is followed by S: S continues P's point. It says that because of this impatience people expect miracles and only a magical transformation can convince them.
S is followed by Q: Q tells us what happens because of S. It says that since the people expecting miracles do not get one, it is their general tendency to find a fault in the system.
Q is followed by R: R elaborates on S' point. It says that due to this tendency, the people condemn and criticise the government. S6 adds a condition after R. It says that the people, however, must realise the truth that perfection is attained in slow proportions to the amount of labour they put in.
Thus, the correct sequence is P S Q R. Hence, A is the correct option.