Answer:
The third one
Step-by-step explanation:
Hey There!
Just so you know when you try to find the complementary base strand you put the letter of the nucleotide that it pairs with
Guanine pairs with Cytosine
Thymine Pairs with Adenine
Adenine Pairs with Uracil
Cytosine Pairs with Guanine
If you have anymore questions feel free to ask :)