The phrase that defines a sound argument is "A sensible and valid statement" (Option 4).
The correct phrase that defines a sound argument is option 4: "A sensible and valid statement." A sound argument is one in which the premises (statements supporting the argument) are true, the reasoning is logical, and the conclusion logically follows from the premises. To determine if an argument is sound, you need to evaluate the truth and validity of its premises and the logical connections between them. In this case, options 1 and 2 aren't related to arguments, and option 3 describes an impractical analysis that is difficult to prove, which would not be considered a sound argument. However, option 4 describes a statement that is sensible (reasonable) and valid (logically sound), making it the correct choice.
