What is alternative obligation?

The rule on alternative obligations is governed by Article 1199 of the Civil Code, which states:
ART. 1199. A person alternatively bound by different prestations shall completely perform one of them. The creditor cannot be compelled to receive part of one and part of the other undertaking. (1131)
An alternative obligation is one wherein various prestations are due but the performance of one of them is sufficiently determined by the choice which, as a general rule, belongs to the debtor.[1] 

Things to remember in an alternative obligation:

a) of the two or more prestations, several are due;

b) may be complied with by performance of one of the prestations which are alternatively due;

c) the right of choice belongs to the debtor, unless it has been expressly granted to the creditor;

d) loss/impossibility of all prestations due to a fortuitous event shall extinguish the obligation;

e) loss/impossibility of one of the prestations does not extinguish the obligation; and

f) culpable loss of any of the objects alternatively due before the choice is made may give rise to liability on the part of the debtor.

[1] 8 Manresa 176.