Final answer:
In his research, William Sheldon found that the mesomorph body type was more common among offenders. However, his theory is not widely accepted. The ectoderm is the embryonic layer responsible for the development of skin cells.
Step-by-step explanation:
In 1949, William Sheldon found that offenders were more likely to be b) Mesomorphs. This conclusion was a part of Sheldon's theory that connected body types with temperaments and likelihood to exhibit certain behaviors. However, it is important to note that this theory has been largely discredited in modern times.
Now, addressing the reference information provided, when discussing which of the layers of the embryo gives rise to skin cells, the correct answer is a) ectoderm. The ectoderm is the outermost layer of an embryo that eventually develops into the skin and nervous system, among other structures.