Answer: The correct answer is -
A. Sense strand of DNA, substituting uracil for thymine.
Step-by-step explanation:
Transcription is a process of formation of mRNA (messenger RNA) using a DNA template with the help of enzyme RNA polymerase.
In this process, ribonucleotides are added by RNA polymerase in 5' to 3' direction (that is antiparallel to the direction of template DNA) in a complementary manner.
For Adenine, uracil is added and for Cytosine, Guanine is added in mRNA. This produces the mRNA transcript matching the sense strand of DNA (that is complementary to antisense or template DNA).
Thus, option A) is the right answer.