What other structures travel to the injury site with the white blood cells?

I think it is antibodies because both antibodies and white blood cells both deal with disease and injuries 

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.