Testify :

The correct answer is: E. Witness.

To testify is to give evidence in a court of law. A witness is someone who gives evidence in a court of law.

A. Falsify means to make something false or untrue.
B. Evidence is anything that can be used to prove or disprove something.
C. Prove means to show that something is true or correct.
D. Confide means to tell someone something secret or private.

Here is a sentence using the word “testify”:

The witness testified that she saw the defendant commit the crime.