Which of the Statements About Cathodic Protection of a Metal

Which of the statements about cathodic protection of a metal pipe against corrosion is correct?

A) The metal pipe is protected by attaching an active metal to make the pipe the cathode in an electrochemical cell
B) The metal pipe is protected by coating the pipe with another metal whose standard reduction potential is less negative than that of the pipe
C) The metal pipe is protected by attaching a dry cell to reduce any metal ions which might be formed
D) The metal pipe is protected by attaching an active metal to make the pipe the anode in an electrochemical cell
E) The metal pipe is protected by coating the pipe with a fluoropolymer to act as a source of fluoride ion (since the latter is so hard to oxidize)