Final answer:
The correct statement indicating successful teaching by the nurse is c) I'll inform my healthcare provider if I experience severe headaches. Severe headaches during pregnancy can signal complications, which is why it's critical that the client reports them to their healthcare provider.
Step-by-step explanation:
The nurse determines the teaching is successful if the prenatal client makes the statement: c) I'll inform my healthcare provider if I experience severe headaches. This is because severe headaches may be a sign of complications such as preeclampsia. It is important for pregnant individuals to watch for warning signs like this that could indicate potential complications during pregnancy. Option a) regarding an increase in fetal movement is not correct, as fetal movement is expected to increase and is generally a healthy sign. Option b) mentions swelling of ankles and feet, which can be normal to some extent due to the increased blood volume during pregnancy, but could also indicate other issues if excessive or accompanied by other concerning symptoms. Option d) regarding gaining 20 pounds in the first trimester is not expected and can be a sign of abnormal weight gain.