I Am Fascinated By Human Behavior

It's interesting to see how people react in certain instances. Let's say you and the person you love the most were on a ship that was sinking 275 km from the nearest port with only 15 minutes until it's completely under water and there is a serial killer aboard. In total there are only you, the person you love the most, and the killer because everyone else is dead or drowned and the sinking ship only has one life vest because the killer destroyed the others. In such a situation would you a:take the life vest yourself and abandon the one you love with the killer and a sinking ship or b: give the life vest to the one you love and risk being killed by the serial killer or drowning? Of course there is also always a third option if you believe it will work without being killed, drowning, killing, or losing the person you love but best give a very detailed plan for that. So choose either a, b, or c (making your own plan that has to be both reasonable and no misfortune)