What does it mean to say that extension by DNA polymerase Ill proceeds 53'? O The 5' end of a DNA polymerase molecule attaches to the 3' end of primase. O DNA polymerase adds nucleotides to a growing strand, moving in the 5 3' direction. A DNA polymerase seals nicks as it moves along a DNA strand toward the 3' end. O DNA polymerase can only synthesize DNA at the 5' end of an existing strand of DNA.