Answer:
The endocrine glands that produce the steroid hormones, such as the gonads and adrenal cortex, arise from the mesoderm. In contrast, endocrine glands that arise from the endoderm and ectoderm produce the amine, peptide, and protein hormones. Because the endocrine glands play pivotal roles both in reproduction and in development, it seems plausible to extend the role of the endocrine system to account for the progressive changes in body structure and function that occur with aging. changes occur that affect the endocrine system, sometimes altering the production, secretion, and catabolism of hormones. For example, the structure of the anterior pituitary gland changes as vascularization decreases and the connective tissue content increases with increasing age. This restructuring affects the gland’s hormone production. For example, the amount of human growth hormone that is produced declines with age, resulting in the reduced muscle mass commonly observed in the elderly.
The answer is the IntraCellular Fluid (ICF)
Epidemiologists are scientists who study diseases within populations of people. In essence, these public health professionals analyze what causes disease outbreaks in order to treat existing diseases and prevent future outbreaks.
Therefore the most precise answer is
D) it states both their analytical work (to study causes and patterns) and also what they pretend to achieve(to contain or treatment) but doesn't fully answer the question "Why their concern is so diverse"
A) Does not only give a full valid definition but answers the question "why they concern is so diverse (extensive)?"
because they study "ALL" diseases..
Thus, the correct answer is A