Given below are four jumbled sentences. Select the option that gives their correct order.

A) Before germ theory, the methods taken to avoid illness and infection were based on guesses rather than facts.

B) Developed between 1850 and 1920, germ theory holds that certain diseases are caused by the invasion of the body by microorganisms.

C) Research by Louis Pasteur, Joseph Lister, and Robert Koch contributed to public acceptance of the once-baffling theory.

D) The processes such as fermentation and putrefaction, as well as diseases such as cholera and tuberculosis, were caused by germs.