The correct answer is (b) Latitude.
As the earth is spherical in shape the sun's rays strike the earth at different angles so different parts receive different solar radiation. The amount of radiation received depends on the earth's axial tilt of the earth.The city situated near to equator is more warmer than the city which is not close to equator. Florida is much closer to the sun as compared to New York and seems to be much warmer as compared to New York even in winter and summer because of the latitude.