Answer :

The best answer to the question "¿Qué hace un testigo?" is "Testifica."

Here's why:
1. A testigo, which translates to "witness" in English, plays a crucial role in legal proceedings by providing testimony or evidence about what they have seen, heard, or experienced.
2. Testificar means to testify or give evidence in court or before a legal authority. It involves sharing information or recounting events related to a case based on what the witness knows firsthand.
3. In the context of the options provided, "Testifica" is the most accurate and relevant choice as it directly aligns with the role and responsibilities of a testigo in a legal setting.

In summary, when a testigo is asked "¿Qué hace un testigo?" the appropriate response would be "Testifica," indicating that a witness testifies or provides evidence based on their firsthand knowledge of an event or situation.