Answer:
A five-line poem written with one couplet and one triplet.
An appropriate summary for the article "A Most Troublesome Element" is the last option - C. Arsenic is a naturally occurring, poisonous element that has threatened the health of humans since the Middle Ages.
It clearly states what the whole article is about.
Simile, because a simile needs like or as in the sentence
It allows him to hear the war drum that forces him to kill. The acute silence makes the narrator so uncomfortable, he must make the old man scream. The narrator thinks that only killing the old man will make all of the surrounding noises disappear
