CDS Geography Hydrosphere — Oceans, Rivers and Water Cycle Ocean Currents Questions

Consider the following statements regarding ocean currents :

1. Difference in water density is the main cause for the formation of ocean currents.
2. Density of water depends on temperature, salinity and pressure.
3. As a rule, ocean waters move from areas of higher density to areas of lower density as a current.
   Which of the statements given above is/are correct ?