At which angle of sunlight does the least amount of heating occur?
options:

when the sun is on the horizon (at a near 0 degree angle to the surface)

when the sun is half way up in the sky (at a near 45 degree angle to the surface)

when the sun is directly overhead (at a near 90 degree angle to the surface)

the sun’s rays are always the same.

third option

Explanation:

possibly the third option at 45 degrees (half of a right angle, or like mid-morning) above the horizon the sun's rays strike Earth's surface and spread out over a larger surface area with less intensity, making these regions experience lower temperatures.

i think the answer is a.keratin is the pigment responsible for skin color.