Final answer:
The correct description for the 17-year-old pregnant homeless cocaine addict is a 'vulnerable individual,' highlighting the individual's immediate health risks and social disadvantages.
Step-by-step explanation:
The 17-year-old pregnant individual who is a cocaine addict and homeless can best be described as a vulnerable individual. This description acknowledges the person's exposure to multiple risk factors and the likelihood of facing various obstacles that may harm their health and well-being. The term special population could also potentially apply, as it refers to groups that have distinct health needs and may require targeted health services. However, the primary description that captures the immediacy of the individual's circumstances is vulnerable individual, which places emphasis on the individual's personal health risks and social disadvantages. This term is at the core of various health policies and initiatives, such as Healthy People 2020, which aim to improve health outcomes for populations at heightened risk of poor health behaviors, limited access to healthcare, and adverse health consequences.