Which of the following are correctly punctuated? Check all that apply. Dogs offer companionship to China's older adults, for many of them have only a single grandchild due to China's decades-long one-child policy. Dogs offer companionship to China's older adults. Many of them have only a single grandchild due to China's decades-long one-child policy. Dogs offer companionship to China's older adults many of them have only a single grandchild due to China's decades-long one-child policy. Dogs offer companionship to China's older adults because many of them have only a single grandchild due to China's decades-long one-child policy