The answer is the antibiotics could unintentionally kill good bacteria living in your intestines, leaving you more susceptible to infection by pathogenic bacteria.
Antibiotics will indiscriminately kill any of the bacteria they come into contact with that have similar characteristics to the pathogen being targeted. This can cause trouble because many helpful bacteria live in your large intestine. Antibiotics target bacteria and not viruses. If you take antibiotics it is important to restore any good bacteria in your gut by taking probiotics at the same.
Answer:
1.) abstinence
2.) vaccination
3.) condoms
Explanation:
You didn't include the options from the drop down menus that are mentioned in your question, but the above answers are my best assumptions given that abstinence is the only way to 100% effectively prevent STD's/STI's, there are vaccinations available to protect against hepatitis, and condoms are used as a barrier to reduce the risk of STD's/STI's. That could also be answered with "female condom".
