Which layer is the youngest in this image?

Ineed to know why d is the correct answer asap

Name the two stages involved in protein synthesis and explain what occurs in each of the two stages. be sure to also indicate where each process takes place. plz don't give one sentence answers : d

Agene pool: a) is the collection of all the alleles found in a single species b) is the collection of all the alleles found in a single population c) is the collection of all the chromosomes found in a single population d) is the collection of genes in a species that allow the individuals to swim