The answer would be the plot I believe, but you put it in the wrong subject.
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.
By contracting, muscles pull on bones and allow the body to move.
No i dont think so precautions are needed sometimes