Final answer:
The correct understanding of the patch's usage involves changing it weekly for 3 weeks and having a no-patch week for menstruation.
Step-by-step explanation:
The patient's statement that indicates an understanding of the nurse's teaching on the use of the combination of ethinyl estradiol/norelgestromin, commonly known as the birth control patch, would be: "I will change the patch once a week for 3 weeks and not use a patch on the fourth week to have a period." This is because the birth control patch is designed to be used in this manner to mimic a woman's natural menstrual cycle and prevent ovulation. It is not required to be taken on an empty stomach, smoking is not safe while using any combination of estrogen and progestin birth control due to the increased risk of blood clots, and it is generally not recommended to rely solely on the patch as the only form of contraception.