Final answer:
Stressors during the prenatal stage include smoking, alcohol, and drugs, which are teratogens that can harm fetus development, leading to conditions such as fetal alcohol spectrum disorders.
Step-by-step explanation:
The development of a fetus can be significantly affected by various prenatal stressors. The correct answer to the question about stressors during the prenatal stage is: b. smoking, alcohol, and drugs. These substances are known as teratogens, which are environmental agents that can cause harm to the developing fetus. For instance, alcohol consumption can lead to fetal alcohol spectrum disorders (FASD), which include a range of cognitive, developmental, and physical impairments. Additionally, illegal drugs and some medicines can cross the placenta and affect the development of the fetus.
It's essential for pregnant women to avoid exposure to these harmful substances, especially during the first eight weeks after fertilization, as this is the period when major organs are forming. Pregnant women should also ensure that they are receiving adequate nutrients like folic acid, calcium, iron, and omega-3 fatty acids, which are critical for normal growth and development of the fetus. In contrast to the harmful effects of smoking, alcohol, and drugs, a vegetarian diet of greens, fruits, and dairy products, as mentioned in option a, is not necessarily a stressor during pregnancy, unless it's deficient in crucial nutrients. Heavy exercise like running and swimming or a complete lack of exercise can also influence prenatal development but are typically not classified as teratogens. Each of these factors needs to be examined in the context of individual circumstances and within the guidance provided by healthcare professionals.