Which of the following is considered the most common complementary and alternative medicine (CAM) in the United States?

Natural products are considered the most common form of complementary and alternative medicine (CAM) in the United States. This category includes a wide range of herbal supplements, vitamins, minerals, probiotics, and other naturally sourced remedies used to promote health and well-being. The popularity of natural products can be attributed to their accessibility and the perception that they are more "natural" or safer than pharmaceutical medications.

Additionally, many people often seek out these products for various health concerns, making them a fundamental part of the CAM landscape. The rise of awareness regarding holistic health and wellness has also contributed to the increasing use of natural products.

In contrast, while homeopathy, acupuncture, and chiropractic care are recognized as important components of CAM, their usage is not as widespread as that of natural products. Each of these modalities has its dedicated following and specific applications, but they do not reach the same overall prevalence when it comes to patient choices in the United States.