In Order for DNA to Replicate in a Semi-Conservative Manner,what

In order for DNA to replicate in a semi-conservative manner,what must occur? 1.The double stranded parent DNA molecule must be separated by breaking the hydrogen bonds between the nitrogenous bases
2) Both parent strands of DNA must serve as a template for the synthesis of the new strands
3) The parent strands of DNA must re-anneal after serving as a template for the synthesis of new DNA.

A) 1
B) 2
C) 3
D) 1 and 2
E) 2 and 3