The answer is B: Diction.
Explanation for each option:
A. Parallelism: This rhetorical device involves using similar structures in a series of words, phrases, or clauses. It is not applicable here because the focus is on the choice of specific words rather than the structure of the sentence.
B. Diction: This refers to the choice and use of words in writing or speech. The author’s use of words like "cruelty" and "barbarous" is an example of diction, as these words are deliberately chosen to convey a strong emotional response and to characterize actions or behaviors in a negative light.
C. Inductive reasoning: This is a logical process in which multiple premises, all believed true or found true most of the time, are combined to obtain a specific conclusion. The use of specific words does not constitute inductive reasoning.
D. Ethos: This rhetorical device involves establishing credibility or ethical appeal. While the use of emotionally charged words can contribute to ethos by influencing the audience's perception of the speaker's character, the primary focus here is on the word choice itself, which is more directly related to diction.