Question

janet is writing a research paper about the use of radiation in cancer treatment. she has located a source she wants to use: an article published in a peer - reviewed journal focused on cancer research, written by david sparks, m.d. in 1976. why might this source not be credible?

a. it is not likely to be unbiased.
b. its findings have not been verified.
c. it was not written by a researcher.
d. its information may be out of date.

Explanation:

The article was published in 1976. Medical knowledge, especially in cancer - treatment using radiation, has likely advanced significantly since then. So the information may be out - of - date.

Answer:

D. Its information may be out of date.