[单选题]
4. Which of the following are altered by epigenetic factors during the(( jfrr 2 y 93 v+c/,fwz;nnibvembm)bzelz q..wxk9t 7aczo)f5*+ffyf6 wy+ life of an or)7ezf+y.zof c*f5awfkt6+xlwqy9z . ganism?
A. DNA base sequences.
B. The phenotype of the organism.
C. The genotype of an organism.
D. The function of a protein.