We should not encourage indiscipline.

The correct answer is: B. Indiscipline should not be encouraged by us.

The other options are incorrect because they use the wrong verb tense or form.

• Option A, “Indiscipline should have not encourages by us,” uses the past perfect tense, which is not appropriate for this sentence. The sentence is about a general rule, not a specific event that happened in the past.
• Option C, “Indiscipline should not being encouraged,” uses the present participle form of the verb, which is not appropriate for a sentence that expresses a prohibition.
• Option D, “Indiscipline should not been encouraged,” uses the past participle form of the verb, which is not appropriate for a sentence that expresses a present or future action.

The correct sentence should be: “We should not encourage indiscipline.” This sentence uses the simple present tense, which is appropriate for expressing a general rule. The verb “encourage” is in the negative form, which expresses a prohibition.