What is the tone of the following excerpt from Edgar Allan Poe’s "The Masque of the Red Death"? A. eager and enthusiastic B. mournful and timid C. macabre and suspenseful D. hopeful and reassuring

I think the answer would be C macabre and suspenseful, because the excerpt doesn't  actually explain what exactly way he killed them.

The sentence "they had already taken out the metallic element which is the valuable part" confirms the meaning of pitchblende.

Explanation:

Pitchblende is a mineral that is a type of ''uraninite'' and it is mostly arise in ''veins'' that appears in a black color. They are affiliated with ''silver ''and it is described as the principal source of ''uranium'' and ''radium''. Due to its "black color and high density" it is known as pitchblende.

The formula for pitchblende is .Since the black mineral clue is given, the best choice would be "the metallic element which is a valuable part taken already".