You are a network technician. On Monday morning, you receive a phone call, saying that some computers will disconnect to the network. After examination, you discover that the computers left on over the weekend work normally and those that were shutdown over the weekend stop working. According to the above information, do you know what causes this issue?

A.
DHCP is not functioning.

B.
LDAP is not functioning.

C.
WINS needs to be restarted.

D.
DNS is not functioning.