Final answer:
The techniques for galvanic protection are cathodic protection and sacrificial protection, with the latter often involving galvanization by a more reactive metal like zinc to protect a less reactive metal like iron.
Step-by-step explanation:
The two techniques used for galvanic protection are cathodic protection and sacrificial protection, making the correct answer option 2) Cathodic protection and Sacrificial protection. Cathodic protection involves converting the metal that needs to be protected into the cathode of an electrochemical cell, preventing its corrosion.
Sacrificial protection, often achieved by galvanization, uses a more reactive metal like zinc as a sacrificial anode to corrode preferentially, thereby protecting the underlying metal such as iron. When the zinc layer is compromised, cathodic protection still helps prevent the iron from corroding. Sacrificial anodes need to be monitored and replaced periodically to continue protecting the metal.