S1. When the prestation is negative and the debtor is precluded from doing an impossible or unlawful condition, the entire obligation, including the condition, is null and void. S2. In an obligation subject to a period, what is suspended is the birth of the obligation.

[A] both are true

[B] both are false

[C] only S1 is true

[D] only S2 is true

A brief explanation of your answer. Thanks