A. Age
Age is the best answer because it is easily determined and since there are stages of development, age can tell staff other things such as coordination level, ability and risk of getting hurt.
I'll go through the other answers briefly.
B. Intelligence. Intelligence is a fair enough answer, save for the fact that it is something that is not easy to determine quickly and hence, it would be difficult to determine each child's intelligence before they came into the daycare. Furthermore, intelligence or lack thereof does not necessarily mean that the child does not need as much supervision.
C. Previous training. This is not the correct answer because it is the previous training "of the children cared for." The children do not need to have previous training. It could work as an answer if it were in relation to the workers, not the children.
D. Coordination. Somewhat of a good answer. However, once again, coordination is not an easy determinant, and cannot always reliably predict how many staff should be with how many children.
Answer:
A. RNA
Explanation:
Genes go from DNA to (m)RNA via transcription. Then, RNA is converted to protein via translation. For eg, the insulin hormone is a peptide hormine (peptide is basically protein) which comes from insulin mRNA which was the result of transcription of insulin gene in beta islet cells of pancreas.
Malnutrition is not having enough of the needed nutrients (not having a good diet, eating a lot of unhealthy food but still eating) this could be from either under consumption or over consumption. While under-nutrition is when someone eats an inadequate amount of food for an extended period of time (not eating enough food in general).