"in humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait."if two individuals homozygous dominant for this trait have a child, what is the chance that the child will not be able to roll his tongue? (lo 14.3)

There is a 0 percent chance 

Ibelieve the answer is relative humidity  because it makes more sense that way. solar flares usually occur in space it doesn't affect the earth, well it could but it wont make a significant damage.  latitude is land it doesnt do anything. prevailing winds, i dont know the correct meaning for this but i doubt that affects the land so it has to be relative humidity.