Option B would be your answer. The use of using steriods would then affect the form of the mens breast size. No facial hair will affect this, nor will a voice get deeper. It's only the breast that will be affected.
Answer: Natural Errors
Explanation: Mutagens can erase parts of DNA that then replicate, but is not a mistake made in copying DNA so that's not it. UV Radiation distorts DNA, but is not necessarily a mistake made in copying it. Natural Errors are mutations made by cells when they copy base pairs and ineffectively or for some other reason mutate/do not create the correct DNA, and the failure of cells to correct this is a mutation. This is also known as an error in DNA replication
Answer: Public health measures such as pure food and water, and development of immunizations against many serious diseases such as polio and smallpox, coupled with enhanced economic conditions, are together credited with substantial reductions in the burden of infectious diseases.