Helen Has Written an Article in a Popular Woman's Magazine

Helen has written an article in a popular woman's magazine exploring the many benefits of a cream she has developed and markets on the Internet. Helen asserts this cream has increased sexual responsiveness for nearly all the women who have tried it, although she does not explain how many women have reported this benefit, or what methods she used to determine if it was helpful for them. Helen does not list her educational credentials. Why should one be skeptical of Helen's claims?

A) The magazine is not a peer-reviewed publication, and there is no evidence Helen is a trained researcher.
B) Helen is likely to benefit financially from her findings that the product works.
C) Because Helen does not describe her research methods, it is impossible to judge their quality.
D) All of the above.