Fact 1: Tidal energy can be used to produce electricity.

Fact 2: Ocean thermal is energy derived from waves and also from tidal waves.

Given the two facts above, answer the question "What can be used to produce electricity?" with the following options: 
- light bulbs
 - waves
 - wind
 - headphones
 - rivers
 - coal
 - motors
 - viruses


 

  waves       