The answer is D. Power : Machine.
In all the other options, the first item is a necessary component of the second item. For example, oil is necessary for a lamp to work, water is necessary for a tap to work, and oxygen is necessary for life to exist. However, power is not a necessary component of a machine. A machine can work without power, for example, if it is powered by human or animal labor.
Here are some additional details about each option:
- A. Oil : Lamp
Oil is a necessary component of a lamp because it is what allows the lamp to produce light. Without oil, the lamp would not be able to work.
- B. Water : Tap
Water is a necessary component of a tap because it is what allows the tap to dispense water. Without water, the tap would not be able to work.
- C. Oxygen : Life
Oxygen is a necessary component of life because it is what allows living things to breathe. Without oxygen, living things would not be able to survive.
- D. Power : Machine
Power is not a necessary component of a machine. A machine can work without power, for example, if it is powered by human or animal labor.