The correct option is D a good person
A noun phrase is a group of words containing the noun and functioning as a subject, object, or preposition of an object, in a sentence. In the given sentence, "a good person" contains a modifier "good" (adjective) and a noun "person", it performs as an object in the sentence; hence it's a noun phrase and option D is correct. "Going" and "travelling" are gerunds, when placed in the sentence they're not relevant in terms of context. Hence none of them are the suitable options and, A and C are incorrect. "Good" is an adjective, it's not a noun phrase hence option B is incorrect.