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 (first option) is a means of energy transfer but not the definition of energy itself. A disturbance (second option) also relates to energy transfer (like in waves) but is not the core definition. Pressing to make more compact (fourth option) is about compression, not energy.

Answer:

the ability to do work