In the TCP 3-way handshake:
P1 (SYN = 1): The first packet (P1) is sent by the client to initiate the connection, and it has the SYN flag set to 1.
P2 (SYN = 1, ACK = 1): The second packet (P2) is sent by the server to acknowledge the client's request. It has both SYN and ACK flags set to 1.
P3 (ACK = 1): The third packet (P3) is sent by the client to acknowledge the server's response. It has only the ACK flag set to 1.
Thus, options (B) and (D) are correct:
(B) P2: SYN = 1, ACK = 1.
(D) P1: SYN = 1.
Why Other Options are Incorrect:
Option (A): Incorrect because P3 only has the ACK flag set, not both SYN and ACK.
Option (C): Incorrect because P2 has both SYN and ACK flags set, not just ACK.