Well the most appropriate answer is C, the skin layer is a layer of cells. These layers are constantly subject to the UV spectrum in which causes DNA thimer dimerisation to occur. This leads to DNA damage and thus cancer.
I guess D makes sense in that some chemicals cannot be absorbed (charged chemicals)
Answer:
1. The use of protein as an energy source is greater for endurance athletes than for those who body build or lift weights.
2. Protein and amino acid supplements are needed as energy sources for weight lifters.
