Final answer:
The formal affirmative command in Spanish is used to give orders or instructions using the usted form of the verb.
Step-by-step explanation:
The correct option is O Cubre la cabeza.
In Spanish, the formal affirmative command is used when giving orders or instructions to someone using the usted form. To form the formal affirmative command, you usually drop the subject pronoun and use the third person singular form of the verb.
For example, in the given options:
- O Beba agua is the formal negative command (Don't drink water)
- O Descanso esta tarde is the informal affirmative command (Rest this afternoon)
- O Tose más is the informal negative command (Don't cough more)
Learn more about Formal affirmative command in Spanish