The answer is B: CGT
According to the base pairing rules, in DNA, adenine pairs with thymine (A-T), and cytosine pairs with guanine (C-G).
The complementary triplet for GCA is CGT. So, for the DNA segment AGT CAC GCA, the complementary strand will be TCA GTG CGT:
Known strand: AGT CAC GCA
Corresponding strand: TCA GTG CGT
