Arrange the sentences A-D in the correct sequence to form a coherent paragraph. S1 and S2 are the first and last sentences. S1-  Optimism is not a deep,complicated philosophy.  A-In some persons it is an inborn trait.  B- In fact ,it is always talking a positive and bright view of life.  C- It is more of a general attitude of life.  D- They are tuned that way by nature and temperament . S2- However in most cases it is an acquired and nurtured habit.