The act of taking ones life

Suicide is the correct word.
Suicide is the intentional killing of oneself, or the taking of one's own life. "The despondent woman committed suicide," for example. As a result, Option 1 is right. Among the other alternatives, slaughter means to kill an animal for food, homicide means murder, and immolation means to kill yourself or someone else, or to destroy something in a ceremonial ritual, generally by burning. These selections are inappropriate because they do not express the required meaning.