What Are the Major Disadvantages of Using Ozone Instead of Chlorine

What are the major disadvantages of using ozone instead of chlorine to disinfect water?

A) Ozonation is more expensive than chlorination and ozone leaves an odor in the water.
B) Ozonation causes trihalomethane formation and leaves an odor in the treated water.
C) Ozonation causes trihalomethane formation and is more expensive than chlorination.
D) Ozone does not provide long-term protection against waterborne viruses because it decomposes quickly and it is more expensive than chlorination.