Direction: Each of the following questions consists of six sentences of a passage. The first and sixth sentences are given as S1 and S6. The middle four sentences in each have been jumbled up and labeled as P, Q, R, and S. Find the proper sequence of the four sentences and mark your response accordingly.

S1: Diseases caused by microorganisms or bacteria, which can transmit from a diseased person to a healthy person are `communicable diseases.’

P: Pathogens include fungi, bacteria, viruses, protozoa, parasites, and worms.

Q: It is better to prevent diseases than to treat and cure them by medically treating them after they take place. 

R: These diseases can be transmitted through the air or are spread from person to person by direct contact.

S: In other words, communicable diseases are caused by pathogens that can pass from one person to another. 

S6: However, diseases can be prevented by vaccination.