Because you know someone might be in danger. Guide dogs are really important for their owners, its a job. They're not just pets for them but also someone they depend on and someone they trust.
The answer is: b) It suggest a sudden act of violence
In this poem Poe is talking about Annabel Lee and how she dies, in the underlined words “Chilling and Killing” we can see that the envious angels, send a win to get Annabelle and this cloud came and end her life, this is sudden act of violence influence by the envy that the angel felt for the happiness of Annabel Lee.
