What can be said about the mother and son in the passage?

Đáp án A
Thông tin ở đoạn cuối:
- After making their next appointment, they both took out their cell phones, placed calls, and began loud conversations with whoever was on the other end.
- They both jumped into their SUV, and, as I saw them drive off, they were still talking on their cell phones. But, alas, not to each other. (Họ nói chuyện trên điện thoại chính mình, chứ ko giao tiếp với nhau)