What does it mean to have a 'heart of steel'?

1. a poem that tells a story irony 2. taking on human characteristics narrative 3. a direct comparison between two things personification 4. words that are opposite the thoughts in a speaker's mind simile 5. implied comparison introduced with "as" and "like idiom 6. one's own manner of speaking metaphor

Which of the following is an example of a periodical?

In the song mallam sile sings in lines 113 through 130 the knife probably represents