The factors that contribute to Mercury's daily temperature fluctuation of about 600°C are the planet's slow rotation and

A. its close proximity to the sun.

B. its dense atmosphere.

C. its heavy, rocky, water-less terrain

D. the absence of a thick atmospheric layer to regulate temperature.

D. the absence of a thick atmospheric layer to regulate temperature.

Explanation:

Mercury is the smallest and closest planet to the Sun. On its surface, Mercury's temperatures are extreme, reaching up to 600 ºC in the daytime and dropping to around -180 °C in the nighttime. This huge variation in Mercury's surface temperatures is due to the fact that this planet doesn't have an atmosphere to retain the heat at the night. Therefore, the heat during sunlight hours cannot be distributed on the surface of this planet, and temperatures at the poles can be hundreds of degrees below zero.

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