The correct answer is A. Killer : Death.
A sadist is someone who enjoys causing pain to others. A killer is someone who takes another person’s life. Both sadists and killers cause harm to others, but in different ways. Sadists enjoy the act of causing pain, while killers may enjoy the act of killing or may simply be motivated by other factors, such as financial gain or revenge.
The other options do not have the same relationship as the original pair of words. A teacher is someone who educates others, while a pupil is someone who is being educated. An injury is damage to the body, while a bandage is a piece of cloth or other material used to cover and protect an injury. Alcohol is a substance that can be consumed to produce intoxication, while a dipsomaniac is someone who has an uncontrollable craving for alcohol.