When locating an XDSL fault, which of the following is not the reason that users of the entire frame device cannot access the Internet?

When locating an XDSL fault, which of the following is not the reason that users of the entire frame device cannot access the Internet?
A . The device’s main control board is faulty
B . Cyberattacks
C . Power Supply Problems
D . Some XDSL board failures

Answer: D