The overall number of cases of STIs is:

Choice A reason: Insulin is the preferred medication for gestational diabetes mellitus, as it does not cross the placenta and has no adverse effects on the fetus. It can be administered subcutaneously or intravenously, depending on the blood glucose level and the type of insulin.

Choice B reason: Glipizide is an oral antidiabetic agent that belongs to the sulfonylurea class. It stimulates the pancreas to secrete more insulin and lowers the blood glucose level. However, it is not recommended for gestational diabetes mellitus, as it can cross the placenta and cause hypoglycemia, macrosomia, or teratogenic effects on the fetus.

Choice C reason: Acarbose is an oral antidiabetic agent that belongs to the alpha-glucosidase inhibitor class. It delays the absorption of carbohydrates from the intestine and reduces the postprandial blood glucose level. However, it is not recommended for gestational diabetes mellitus, as it can cause gastrointestinal side effects, such as flatulence, diarrhea, or abdominal pain, and may interfere with the absorption of other nutrients.

Choice D reason: Repaglinide is an oral antidiabetic agent that belongs to the meglitinide class. It stimulates the pancreas to secrete more insulin and lowers the blood glucose level. However, it is not recommended for gestational diabetes mellitus, as it can cross the placenta and cause hypoglycemia, macrosomia, or teratogenic effects on the fetus.

Choice A reason: The incidence of hepatitis C is not decreasing, but rather increasing, especially among young people who inject drugs. Hepatitis C is a chronic infection that can lead to liver damage and cancer.

Choice B reason: Hepatitis B is more contagious than HIV, as it can be transmitted by blood, semen, vaginal fluids, and other body fluids. Hepatitis B can also cause chronic infection and liver problems.

Choice C reason: A vaccine exists for hepatitis B but not for hepatitis C. Hepatitis B vaccine is recommended for all infants, children, and adults who are at risk of exposure. Hepatitis C vaccine is still under development.

Choice D reason: Hepatitis A is caused by eating contaminated food or drinking polluted water. It is an acute infection that usually resolves on its own. Hepatitis A vaccine is available for travelers and people who live in areas with poor sanitation.