The DNA bases $A,T,G$ and $C$ form complementary base pairs in double$-$stranded DN When DNA is being replicated how does DNA$-$dependent DNA polymerase ensure that A$\text{'}$s always pair with T$\text{'}$s and G$\text{'}$s always pair with C$\text{'}$s$?$

a$.$ The natural affinity of A with $T$ and $G$ with $C.$

b$.$ The formation of specific hydrogen bonds exclusive to the A$-$T and G$-$C pairs.

c$.$ The nuclear reactions characteristic of A$-$T and G$-$C pairs in the nucleus where D replication takes place.

d$.$ The rules of Chargaff who discovered the $1$:$1$ relationship between A$-$T and G$-$C$.$