Final answer:
January and July have different average high temperatures mainly due to Earth's axial tilt, which causes seasonal temperature variations through changes in sunlight angle and daylight length. option B is correct .
Step-by-step explanation:
The difference in average high temperatures in January and July is primarily caused by Earth's axial tilt. During these months, one hemisphere is tilted towards the Sun, receiving more direct sunlight and experiencing summer, while the other is tilted away, receiving less direct sunlight and experiencing winter.
This tilt of 23.5° leads to variations in the angle of direct sunlight and the length of daylight, which directly affects temperature. The tilt of the Earth's axis results in different seasons and is the main reason why January is typically cold in the Northern Hemisphere and warm in July, while the Southern Hemisphere experiences the opposite.