Gardner told lawmakers that it would cost Amtrak $1 billion per year just to keep its Northeast corridor infrastructure in a state of good repair, and would cost another $4 billion per year to complete its backlog of projects on the 457-mile corridor, a span that includes numerous century-old bridges and a 142-year-old tunnel.
Utilize the input text as a context reference, choose the right relationship between 'Northeast corridor' and 'Amtrak' from the options.
Options: chairperson, director/manager, owned by, member of