Question

which phrase accurately characterizes sexually transmitted infections (stis)?
○ are caused by bacteria, viruses, or parasites
○ always cause visible symptoms
○ are rarely transmitted by sexual contact
○ can be contracted only by women

Explanation:

• For the option "are caused by bacteria, viruses, or parasites": STIs like chlamydia (bacteria), HIV (virus), and trichomoniasis (parasite) fit this, so this is correct.
• For "always cause visible symptoms": Many STIs (e.g., HPV in some cases) have no visible symptoms, so this is wrong.
• For "are rarely transmitted by sexual contact": STIs are primarily transmitted sexually, so this is wrong.
• For "can be contracted only by women": Both genders can contract STIs (e.g., gonorrhea in men and women), so this is wrong.

Answer:

A. are caused by bacteria, viruses, or parasites