The word "ebony" in this poem serves to describe the raven and principally relates to its chief feature: colour. Let us examine the line that you are referring to:
Then this ebony bird beguiling my sad fancy into smiling...
A good thing to do if you have a question with a number of possible answers is to go through a stage by stage process of deduction helpfully remembered by the acronym POE: Process Of Elimination. In this sentence, ball and tall do not make sense as possible definitions for "ebony." Good would make no sense either given the general evil atmosphere that surrounds the raven. So that leaves us with bright or none of these. A quick web search will reveal that "ebony" actually means a dark, glossy black, indicating that none of these is the correct answer.