A pronunciation guide is a KEY TO HELP YOU UNDERSTAND THE SOUND OF PRONUNCIATION SYMBOLS.
A pronunciation guide refers to a guide which show how words are to be pronounced, this is usually shown in the form of a list of symbols. The symbols used always integrate articulation, stress and intonation. Dictionaries typically include pronunciation guide which show how to correctly pronounce words.
The correct answer cannot be any of the other choices besides, sequence.
If the answer was "Adding an Idea" it would have to be furthermore, yet, in addition, and other choices.
The only category "Afterword" belongs in is a sequence.