Final answer:
The most valid reason for a person to purchase a specified disease health insurance policy is if their family has a history of cancer and they are concerned about contracting the disease.
Step-by-step explanation:
The most valid reason for a person to purchase a specified disease health insurance policy is B) Her family has a history of cancer, and she is concerned that she might contract the disease. Having a family history of cancer increases the individual's risk of developing the disease, making it a valid reason to purchase a specific disease health insurance policy. This policy would provide coverage and financial protection in case the person contracts the specified disease.