S sold his watch to B in a public document. However, B informed S that he would obtain actual delivery of the watch after 3 days. The day after the sale to B, S sold the same watch to X in a private document and X immediately took possession of the watch. X was not aware of the sale to B. Who has a better right over the watch

a. B because he has the older title.

b. X because he first took actual possession of the watch in good faith.

c. B because he first took constructive possession of the watch in good faith.

d. X because X has not registered the watch in good faith.