Hi!
The correct answer would be B. The first law.
The first law of thermodynamics is also known as the law of conservation of energy, and establishes that energy cannot be created or destroyed, and is only seen to be transformed from one form to another, in an isolated system.
For example, it may seem like pressing a button may generate light energy from a bulb, but it is actually the conversion of electrical energy into light energy.
Similarly, in a circuit run from battery, chemical energy (of the battery) is converted into light energy. This energy is seen to be converted into the form of heat energy which is emitted from the bulb.
Hope this helps!
