Which of the following statements characterizes an important difference between public health and most other professions? (a) education and training beyond the undergraduate (college) level is not available for public health. (b) large professional organizations do not exist for public health. (c) public health professionals work only in the public sector. (d) although they come from many professions and disciplines, their common bond is not one of a shared body of knowledge or academic preparation, but a commitment to the goal of improved population health.