Réponse:
A: The term mutligenerational living could define a way to live and adapt yourself with other generations at different levels in terms of support, and independance. (je suis pas sur de moi mais j'ai pas trouver mieux)
B: American millennials live in mutligenerational houses because it's way more easier to stay with parents while having a job that must not pay enough to have your own residence, and as Gillian said, the economy is therfore crushing them if they're not.
C: Living in this way actually has positive points and negatives points. VOILÀ JE SAIS PLUS QUOI METTRE MAIS J'ESPÈRE JE T'AI AIDÉ BONNE CHANCE