At least five hours
hope I helped
Bacteria grow most rapidly in the range of temperatures between 40 °F and 140 °F, doubling in number in as little as 20 minutes. This range of temperatures is often called the "Danger Zone.
B is the best option. If her friends keep pressuring her to do something she is uncomfortable then she should find new friends. Don't pretend be something your not people should accept Bertha for what she is not for what she drinks.