How does a DHCP server dynamically assign IP addresses to hosts?

A.
Addresses are permanently assigned so that the host uses the same address at all times.

B.
Addresses are assigned for a fixed period of time. At the end of the period, a new request
for an address must be made, and another address is then assigned.

C.
Addresses are leased to hosts. A host will usually keep the same address by periodically
contacting the DHCP server to renew the lease.

D.
Addresses are allocated after a negotiation between the server and the host to determine
the length of the agreement.

Explanation:
DHCP works in a client/server mode and operates like any other client/server relationship.
When a PC connects to a DHCP server, the server assigns or leases an IP address to that
PC. The PC connects to the network with that leased IP address until the lease expires. The
host must contact the DHCP server periodically to extend the lease. This lease mechanism
ensures that hosts that move or power off do not hold onto addresses that they do not need.
The DHCP server returns these addresses to the address pool and reallocates them as
necessary.