I would say the first option
The two new strands are different from each other ,both of them have only one strand from the original DNA and the other strand is complementary . eg if a strand has the following base pairs .. AACCGGT ( consider this as the strands)
TTGGCCA
now they are going to be seperated AACCGGT TTGGCCA
TTGGCCT AACCGGT
as u can see the two NEW strands formed are similar but NOT IDENTICAL to each other .
A. Vili in stomach. And this is because of gluten.