The correct answer is D. In this phase, the sky becomes dark as the umbra, or complete shadow of the moon, totally hides the sun's rays, bathing the earth in darkness.
Step-by-step explanation
When we write a short essay we can rely on main supporting detail sentences that are thematic sentences that support the main statement of the thesis of the text, and minor support detail that are sentences that support the main sentences of an essay. According to the above, the correct answer is D. "In this phase, the sky becomes dark as the umbra, or complete shadow of the moon, totally hides the sun's rays, bathing the earth in darkness" because this sentence is supporting one of the main ideas is "The third phase, called the totality is the specific point when the moon completely covers the sun". This means this detail is not essential but adds extra information about a major supporting detail. So, the correct answer is D.