Answer: The right answer is the B) The onomatopoeia suggests a desperate toll of the bells.
Explanation: Just to elaborate a little on the answer, it can be added that "moaning" and "groaning" are verbs that suggest sadness, so, in spite of the use of assonance and imagery, options A, C, and D should be discarded. By employing words that resemble the sound that bells make, the author is resorting to onomatopoeia, suggesting a frantic and desperate toll that creates a very vivid and persuasive effect.