[单选题]
4. Which of the following are altered by epigelwy(n 0+blcs*netic (vud6;0 zf vz :f s2,mt)psbssfactors during the life of an organism?f; b,m6tvsdsvpz ss:0u2z f)(
A. DNA base sequences.
B. The phenotype of the organism.
C. The genotype of an organism.
D. The function of a protein.