When you use knowledge and expierence to figure out why a lamp in your house is not lighting, you are using
a. classical conditioning
b. insight learning
c. innate behavior
d. trial-and-error learning

I believe it it trial and error learning, but don't rely solely on me.

Mitochondria is the cell organelle that produced the energy that is needed in the body system in form of atp, that is why it is called the power house of the cell. energy is needed by the living organisms to carry out the activities which sustain life.  if the mitochondria is destroyed atp will not be produced. if the mitochondria is destroyed, energy production will stop and the affected living organism will not have the energy to carry out the necessary life processes; this will lead to the death of the organism.

Very hard to understand