Answer:
A pairs with U
C pairs with G
T pairs with A
Explanation:
Transcription is the first process of gene expression and it involves making a complementary strand of mRNA from a DNA template. It begins when an enzyme called RNA polymerase binds to the promoter region of the DNA and signals it to unwind exposing Its nucleotide bases. RNA polymerase reads the bases and adds nucleotides to the RNA strand using complementary base pairing.
Complementary base pairing is a phenomenon whereby hydrogen bonds pair Adenine and Thymine and also Guanine and Cytosine in DNA i.e. A-T, G-C. However, in the newly made RNA molecule, Thymine base is replaced by Uracil, U.
In this case (question),
If the RNA polymerase reads Adenine (A), it pairs it with Uracil (U) in the RNA molecule.
If it reads Cytosine (C), it pairs it with Guanine (G) in the RNA molecule.
If it reads Thymine (T), it pairs it with Adenine (A).
