May I ask for an explanation to each question. Thank you!

TRUE OR FALSE

1. In alternative obligations, all the presentations stated in the obligation must be performed.

2. In alternative obligations, the debtor as a rule has the right to choose which of the possible obligations should be performed.

3. The obligation becomes simple the moment the debtor has communicated his choice to the creditor.

4. Only a possible and practicable obligation could be chosen from among available obligations.

5. When all the obligations set in the alternative are lost without the fault of the debtor, the obligation is extinguished.

6. In alternative obligations, the creditor may have the right to choose the obligation to be performed if the loss is due to the fault of the debtor.

7. In facultative obligations, there is a substitute for the principal obligation.

8. When the principal obligation is valid and the substitute obligations is not, the obligation becomes a simple obligation.

9. In facultative obligations, the right to choose what obligation to perform belongs to the debtor.

10. In conjunctive obligations, several prestations need to be performed.