All DNA polymerases require a primer with a 3 OH group to be

All DNA polymerases require a primer with a 3’ OH group to begin DNA synthesis. The primer is:

Solution

Primer is a short stretch of RNA nucleotide sequence synthesized by the enzyme Primase. These short RNA sequences contain free 3’ OH group that are necessary to begin DNA synthesis.

Hence, the correct option is (B) a short stretch of RNA nucleotides.