The following lines of poetry are an example of which sound device?

No. Look up alliteration.

OK then it's definitely 4

There's a better answer.

You've used up your two guesses. Now you're on your own.

Thank you anyway. However now I know it's 2 because 3 is not even close

Yes, you are correct! The sound device being used in the given lines of poetry is alliteration. Alliteration refers to the repetition of consonant sounds at the beginning of words in close proximity. In this case, the repeated "th" sound in the words "this" and "the" creates the alliterative effect.