The correct statements about warm currents are:
- They make landmasses warmer.
- They are surface currents.
Warm ocean currents generally flow from the equator towards the poles and have a warming effect on the coastal regions they pass by. However, they are typically less dense than cold currents, not denser.
The option that states "They move from the poles to the equator" is incorrect, as warm currents typically move from warmer equatorial regions towards cooler polar regions.
So in summary, the correct options are that warm currents make landmasses warmer and that they are surface currents.