Use the following figure to answer the next few questions.

This figure shows a diagram of blocks of genes on human chromosome 16 and the locations of blocks of similar genes on four chromosomes of the mouse.
-In humans,hemoglobin in the embryo has a higher affinity for oxygen than in adults.What is this due to?

A)nonidentical genes that produce different versions of globins during development
B)pseudogenes, which interfere with gene expression in adults
C)the attachment of methyl groups to cytosine following birth, which changes the type of hemoglobin produced
D)histone proteins change shape during embryonic development
E)different promotors