Which of the following is an example of an unnecessary risk during pregnancy?

Using illicit drugs is indeed an example of an unnecessary risk during pregnancy. The use of these substances poses significant dangers to both the mother and the developing fetus. Illicit drugs can lead to a range of complications, including preterm labor, low birth weight, and developmental issues for the child. Additionally, they can negatively impact the mother's health, increasing the likelihood of addiction and associated risks.

In contrast, consulting a healthcare provider regularly, participating in childbirth education classes, and maintaining a nutritious diet are all beneficial activities during pregnancy. Regular consultations with a healthcare provider help monitor both the mother's and the baby's health, while childbirth education classes prepare expectant parents for labor and delivery, fostering a supportive environment. A nutritious diet is essential for the healthy growth and development of the fetus and can help prevent complications during pregnancy. Thus, while there are many healthy choices to make during pregnancy, the misuse of illicit drugs stands out as a significant and unnecessary risk.