Answer
An mRNA may contain the sequence
ATTGACCCCGGTCAA.
Incorrect.
Work Step by Step
mRNA stands for messenger RIBOSE nucleic acid. RNA is single stranded and different from DNA. DNA can have Adenine, Thymine, Guanine and Cytosine as a nitrogenous base. But RNA will have Adenine, Uracil, Guanine and Cytosine.
This means that no RNA strand can have Thymine as a nitrogenous base. Rendering the sequence above incorrect.