You are presented with the question "what is used to find objects underwater?" and the following answer choices: 
- echolocation
 - a hydraulic system
 - heat energy
 - Electrical energy
 - dolphins
 - mussels
 - by indirect light
 - rays or beams

Now knowing that sonar is used to find the location of an object and active Sonar Active sonars transmit acoustic energy and detect targets by echolocation, choose the best answer.


 

 echolocation        