Do not feed the animals. Visitors must not touch the animals’ cages. What is the mood of the verb in the first of the two sentences?
Indicative
Imperative
Interrogative
Conditional

Which revision corrects the improper shift in mood in the example?
1. Do not feed the animals. Do not touch the animals’ cages.
2. Do not feed the animals. You must not let the animals’ cages be touched.
3. Do not let the animals be fed. You must not touch the animals’ cages.
4. You must not feed the animals. Do not touch the animals’ cages.