Final answer:
The ambivalence or ambiguous feelings about the pregnancy do not make it a high-risk family situation. Risk factors are mainly associated with lack of support, poverty, and being a single teenage parent, not the emotional state of uncertainty.
Step-by-step explanation:
In assessing a high-risk family situation for a pregnant teenager, one must consider various factors that contribute to such a determination. Looking at the provided options, ambivalence or ambiguous feelings about the pregnancy (D) do not inherently make this a high-risk family situation. While it is normal for expectant parents to have mixed feelings, it is not a risk factor in the same way as the lack of social support (A), poverty/low income (B), and being headed by a single teenage parent (C) are. These latter factors can lead to significant stress and challenges in providing for the child's needs. Therefore, ambivalence about the pregnancy does not contribute to the risks associated with a lack of resources and support.