Answer:
B. Chemical energy to electric energy to kinetic energy to sound energy
Step-by-step explanation:
A battery is a device that converts chemical energy, stored in the chemical substance contained inside the battery, into electric energy, by pushing electrons along the circuit at which the battery is connected.
In an MP3 player, this electron (which form an electric current) pass through a sound transducer, which is a device that converts the electric energy of the current into kinetic energy, by producing the vibrations of the loudspeaker (or of the headphones).
As a result, the air surrounding the loudspeakers/headphones start to vibrate, producing sound waves, and the sound that we hear: in this last stage, therefore, kinetic energy has been converted into sound energy.