When DNA Is Heated to Just Below Boiling (90°C-95°C)

When DNA is heated to just below boiling (90°C-95°C) ,

A) the sugar phosphate backbone of the DNA strands breaks.
B) the sugar, phosphate, and base come apart in each nucleotide.
C) the helix unwinds but hydrogen bonds between the bases remain intact.
D) the two DNA strands separate completely.
E) nothing happens until the boiling point is reached (100^oC) .