I'm fairly certain it's the first answer but it may be the third answer as well but I believe it's the first more though.
Onomatopoeia is a figure of speech which imitates sounds heard in nature. Having that in mind, the example of that figure in this poem would be moaning and groaning. The moaning and the groaning of the bells is a reference to the moaning and the groaning that animals and humans can produce.
“Franklin, Benjamin.” Encyclopedia Britannica. 15 Ed., 2002