Scenario: A software application requires testing of various input fields such as username, password, and email address. Which technique would be most suitable for efficiently testing combinations of these input parameters?

Pairwise Testing is the most suitable technique for efficiently testing combinations of input parameters. It allows the testing of all possible pairs of values, providing thorough coverage while minimizing the number of test cases. This is particularly useful when dealing with multiple input parameters, such as usernames, passwords, and email addresses in this scenario.