What is the range of packet sequence numbers that would be accepted by the server?

You want to carry out session hijacking on a remote server. The server and the client are communicating via TCP after a successful TCP three-way handshake. The server has just received packet #120 from the client. The client has a receive window of 200 and the server has a receive window of 250. What is the range of packet sequence numbers that would be accepted by the server?

A.
121-371

B.
120-370

C.
200-250

D.
121-231

E.
120-321

Explanation:
Package number 120 have already been received by the server and the window is 250 packets, so any package number from 121 (next in sequence) to 371 (121+250).