This means it has TWO poles
The 2 poles are NORTH and SOUTH
It would be D I believe! Depending on the angle of the mirror and distance positioned!
The correct answer for this question is this one: "measuring the temperature increase of water from doing work stirring it." This experiment is generally regarded as being first carried out by James Joule is this one, <span>measuring the temperature increase of water from doing work stirring it.</span>