a) By separating the business logic of an application from its
   presentation logic, a multi-tier architecture makes Internet applications
   much more flexible to changes.

b) The dominant transport layer protocol today is called HTTP.

c) When determining the destination socket for a received IP datagram
   that carries a TCP segment, the receiving host must consider both the
   sender's IP address and port and the destination's IP address and port.

d) In TCP, the number of bytes that one party may send before receiving
   an acknowledgement from the other side is fixed by design.

e) Cryptographically signed tokens allow a server to validate a user's
   identity even when the user provided their authentication credentials
   to a different server (called an identity provider.)

f) The network layer uses the transport layer to
   ensure the reliable delivery of network packets.

g) If the transition from IPv4 to IPv6 goes according to
   plan, IPv4 traffic will eventually fade out even before
   users disable IPv4 on their networks.

h) The design of custom transport layer protocols such
   as QUIC requires changes to the OS kernel because all network
   protocol processing takes place inside the kernel.