单选题 A health profile is a portrait of all of the factors that influence your health. To draw your health profile, you will need to know what diseases run in your family, what health hazards you may be exposed to at work, how your daily diet compares to the recommended standards, how much time per week you spend exercising and what type of exercise you engage in, how stressful your work and family environments are, what kinds of illnesses you get regularly, and whether or not you have any one of a number of addictions. To complete this portrait, you should have a checkup to determine how your blood, heart, and lungs are functioning. This checkup will seine as a baseline (基础，起点), to which you can then compare later tests.
A physical checkup on one's blood, heart and lungs serves as

• A. the basis on which one can evaluate his health status.
• B. part of one's health profile.
• C. the starting point of improving one's health.
• D. an example of a health profil