Final answer:
The nucleic acid sequence 'cattcgata' corresponds to a)DNA, as it contains thymine rather than uracil, which would be found in RNA.
Step-by-step explanation:
The sequence "cattcgata" could be a strand of a)DNA since it only contains the nucleobases adenine (A), cytosine (C), guanine (G), and thymine (T), which are typical of DNA.
In contrast, mRNA would contain uracil (U) instead of thymine (T). Therefore, the correct type of nucleic acid for the sequence "cattcgata" would be DNA. For the complementary DNA sequence to "GCTTATAT", the correct sequence would be "CGAATATA", as DNA base pairing rules dictate that cytosine (C) pairs with guanine (G) and adenine (A) pairs with thymine (T).