Which of these choices is / are example(s) of plasma?
All of the above
The plasma state consists of super energetic and super excited particles. These particles are in the form of ionised gases.
Aurora borealis is a phenomenon where the particles in the atmosphere get excited due to radiation from the sun and get ionised.
The fluorescent tube and neon sign bulbs also consist of plasma. Inside a neon sign bulb, there is neon gas and inside a fluorescent tube, there is helium gas or some other gas.