Final answer:
The nurse identifies the 55-year-old woman with a family history of breast cancer as being the most at risk for the development of breast cancer.
Step-by-step explanation:
The nurse identifies the 55-year-old woman with a family history of breast cancer as being the most at risk for the development of breast cancer. Having a family history of breast cancer is considered a significant risk factor because it can indicate the presence of certain genetic mutations, such as the BRCA1 and BRCA2 genes, that increase the risk of developing breast cancer. Additionally, the age of 55 is also a risk factor as breast cancer becomes more common as women get older.