Following the completion of TCP $3$ way handshake process, Host X sends a GET message segment to Host Y$.$ The GET message segment carries a TCP payload of $503$ bytes and the $($relative$)$ sequence number is $1.$ What will be the respective sequence number and acknowledgement number that Host Y will employ as the response of acknowledging the successful receipt of the above message?

Question $4$ options:

sequence number is $1,$ acknowledgement number is $503.$

sequence number is $1,$ acknowledgement number is $504.$

sequence number is $503,$ acknowledgement number is $1.$

sequence number is $504,$ acknowledgement number is $1.$

sequence number is $2,$ acknowledgement number is $503.$

sequence number is $2,$ acknowledgement number is $504.$