Is this a "check all that apply" kind of question? With the exception of tRNA, everything else "codes" for a protein in some sense–and you can even argue that tRNA carries some of the code, just not enough by itself to encode a protein. The closest direct connection between a protein product and its "code" I guess would be mRNA, but only because it is the mRNA that is translated from nucleic acid into protein on the ribosome. But the "code" exists all the way back to both strands of the DNA. I’m not entirely happy with the way the question is worded.