Final answer:
The correct answer is B. person, always a good choice.
Step-by-step explanation:
The correct answer is B. person, always a good choice.
In the given sentence, the phrase 'any person, who is young or old' is used as the subject of the sentence. The phrase 'person, always a good choice' maintains parallel structure and correctly identifies the subject of the sentence.
Parallel structure means using the same grammatical form for similar elements in a sentence. Here, 'person' is parallel to 'outsider', both being noun phrases that serve as subjects in the sentence.