Correct option is D
From the given code language:
"jo ta rod" means "you and me"
"pot ta noc" means "you are good"
"jo mit noc" means "good and bad"
By comparing these phrases, we can see that "ta" means "and" and "noc" means "good". Therefore, "mit" must mean "bad". So, "bad" in that language would be represented by "mit".