When determining the mRNA sequence from the DNA sequence, you'll need to understand the base pairing. "T" (thymine) in the DNA sequence is complemented by "A" (adenine) in the RNA sequence. "A" in the DNA sequence is complemented by "U" (uracil) in the RNA sequence. Keep in mind that uracil is unique to RNA, and thymine is unique to DNA. The other complementing base pair is "C" (cytosine) and "G" (guanine).
For this specific problem, the first mRNA complement would be AUG GGG GGC UCU UCG GGA UAG.
The second mRNA complement would be AUG AAU GGC UCU AAG AAC AAA UAG
The third mRNA complement would be AUG GGG GGC CUU ACU ACG UAG
