The phrase that best describe the word "energy" is letter "C. the ability to do work". The unit most commonly used to express energy is Joules (J) which is also derived from the equation of work which is the product of force and the distance that a body moves parallel to the force applied.
The correct answer among the choices is C. heat and pressure. This is the phenomenon that leads to the formation of metamorphic rocks. Thank you for posting your question. I hope this answer helped you. Let me know if you need more help.
