Answer:
The statement which contains an ironic use of understatement is: The pilot called flying from one side of the Atlantic to the other a simple task of "puddle jumping." So, the right answer over here is Option D.
Explanation:
When an author or a writer wants to make a situation seem less important or significant than it truly is then he/she makes an understatement. This figure of speech offers an ironic effect to a statement and results in saying something opposite than what is expected. In this statement mentioned above, the Atlantic ocean is ironically described as a puddle but it actually means that the Atlantic ocean is gigantic.