Below Is a Double Stranded DNA Composed of One Strand

Below is a double stranded DNA composed of one strand containing ¹⁵N atoms and the other strand containing ¹⁴N atoms.If the cell which contains this DNA is grown for one generation (replication) on ¹⁵N medium and then transferred to ¹⁴N media for a second generation,what would the resulting double stranded DNA molecules look like?

A) Four molecules;each containing one ¹⁴N strand and one ¹⁵N strand.
B) Two molecules;one with a ¹⁵N and a ¹⁴N strand,the other with two ¹⁴N strands.
C) Four molecules;three containing one ¹⁴N strand and one ¹⁵N strand and one molecule with two ¹⁴N strands.
D) Four molecules;one with two ¹⁵N strands,two molecules with two ¹⁴N strands,and one molecule with one ¹⁴N and one ¹⁵N strands.
E) Four molecules;all molecules have ¹⁴N strands.