Question

which best defines energy?
a type of wave that carries energy through space, where there is almost no matter
a disturbance that carries energy form one place to another through matter and space
the ability to do work
pressing to make more compact

Explanation:

Energy is defined as the ability to do work. A wave (whether through space or matter) is a means of transferring energy, not the definition of energy itself. Pressing to make more compact is related to compression, not energy.

Answer:

the ability to do work