It can be inferred from the passage that______.A．the new e-mail service is only free for t

It can be inferred from the passage that______.

A．the new e-mail service is only free for the Sprint customers

B．the new e-mail service is free for all the U. S. customers

C．all cellphone customers must pay for the new e-mail service

D．the new e-mail service is only for the Sprint customers

请帮忙给出正确答案和分析，谢谢！