Final answer:
Babies with fetal alcohol syndrome demonstrate that alcohol is a B) teratogen, an environmental agent that can cause damage to a developing fetus, leading to physical and cognitive defects. No amount of alcohol is safe during pregnancy, as its consumption can lead to various degrees of fetal alcohol spectrum disorders.
Step-by-step explanation:
Babies born with fetal alcohol syndrome (FAS) are proof that alcohol is a teratogen. A teratogen is any environmental agent that causes damage to the developing embryo or fetus. There are various types of teratogens, including biological, chemical, or physical agents. Alcohol is a well-documented teratogen which, when consumed during pregnancy, can lead to a range of developmental issues, collectively known as fetal alcohol spectrum disorders (FASD). The most severe form of FASD is fetal alcohol syndrome, which is characterized by a number of physical and cognitive defects, such as small eye openings, smooth philtrum, thin upper lip, cognitive deficits, developmental delays, and behavioral issues.
It is important to note that any amount of alcohol consumption during pregnancy can be hazardous. Teratogenic effects can be especially profound during specific critical or sensitive periods of fetal development, influencing facial features and brain development. Since FASDs are completely preventable, it is advised to abstain from alcohol during pregnancy and while trying to conceive.