What does the word that contains the stem probably mean?

The prosecution discredited the witness by showing that she had lied in the past.

Responses

to intentionally try to make others not believe
to intentionally try to make others not believe

wanting and convincing others to believe the truth
wanting and convincing others to believe the truth

not able to believe
not able to believe

something that is very true and believable

to intentionally try to make others not believe