<u>Answer:</u>
The fourth statement “That will never work” is assertive.
<u>Explanation:</u>
Assertive means being completely obnoxious and overly confident in oneself. It could even be proven wrong but they don't want to be.
Any sentence that declares or asserts a statement, feeling of an individual, opinions, incidents, events, history, or anything is called an assertive sentence.
Here, "that will never work" shows a strong sense of confidence and means that something is not going to work in the near future or future. That is why this sentence can be categorized into an assertive sentence.