C. CHOOSE THE CORRECT OPTION 1) You SHOULD / SHOULDN'T/HAVE TO eat too many calories, or you'll get fat! 2) She DON'T HAVE TO / DOESN'T HAVE TO / MUST tidy up now. I'll do it later. 3) My brother HAVE TO / HAS TO / DOESN'T HAVE TO wear a tie at his work. He is a lawyer 4) You MUSTN'T/MUST smoke in this office. It's the rule 5) We have a lot of work tomorrow. You MUSTN'T I DON'T HAVE TO be late. 6) I HAVE TO / MUST / DON'T HAVE TO clean the floor today because I cleaned it yesterday. 7) We MUSTN'T/DON'T HAVE TO forget to set the alarms before we leave. 8) Nerea can't come because he DOESN'T HAVE TO / HAS TO / HAVE TO work tomorrow 9) We MUST I DON'T HAVE TO bring your passport or you won't board the plane. 10) You MUSTN'T / DON'T HAVE TO / HAVE TO drink and drive.

1) You SHOULDN'T eat too many calories, or you'll get fat.
- The correct option is "SHOULDN'T" because it advises against eating too many calories in order to avoid becoming fat.

2) She DOESN'T HAVE TO tidy up now. I'll do it later.
- The correct option is "DOESN'T HAVE TO" because it implies that there is no obligation for her to tidy up at the moment, as someone else will take care of it later.

3) My brother HAS TO wear a tie at his work. He is a lawyer.
- The correct option is "HAS TO" because it suggests that wearing a tie is mandatory for his job as a lawyer.

4) You MUSTN'T smoke in this office. It's the rule.
- The correct option is "MUSTN'T" because it prohibits smoking in the office as it is against the rule.

5) We have a lot of work tomorrow. You MUSTN'T be late.
- The correct option is "MUSTN'T" because it forbids being late due to the heavy workload.

6) I DON'T HAVE TO clean the floor today because I cleaned it yesterday.
- The correct option is "DON'T HAVE TO" as there is no necessity for me to clean the floor today since I already did it yesterday.

7) We MUSTN'T forget to set the alarms before we leave.
- The correct option is "MUSTN'T" because it emphasizes the importance of not forgetting to set the alarms.

8) Nerea CAN'T come because he HAS TO work tomorrow.
- The correct option is "HAS TO" because it states that Nerea is obligated to work tomorrow, preventing him from coming.

9) We MUST bring your passport or you won't board the plane.
- The correct option is "MUST" because it stresses the necessity of bringing the passport, otherwise the person won't be able to board the plane.

10) You MUSTN'T drink and drive.
- The correct option is "MUSTN'T" as it firmly prohibits drinking and driving.