The correct answer is: "If the techniques are used to, often the audience will get bored".
Explanation:
Persuasive techniques should be innovative and convincing, not repetitive and doubtful. Persuasive techniques may negatively affect people when they already are some common habits for them, consequently getting them bored all the way during the presentation of ideas. All the other options do not apply to the question because they are lacking in some way or dependant on different contexts.
