Final answer:
Shakespeare's line 'So long lives this, and this gives life to thee' from Sonnet 18 signifies that the poem will survive through time, bestowing immortality on the subject it describes.
Step-by-step explanation:
The phrase "So long lives this and this gives life to thee" from Shakespeare's Sonnet 18 reflects the theme of the enduring nature of poetry and its power to grant immortality to its subjects. When analyzing this line within the context of its couplet, we understand that 'this' refers to the sonnet itself. The translation closest to the original meaning of the entire sonnet, which speaks to the eternal nature of the written word as opposed to transient human beauty, is option b) This poem will survive and it will give you immortality. Throughout the sonnet, Shakespeare explores how the youth's beauty can be preserved within the lines of his verse. Therefore, the sonnet itself ('this') will live on as long as people can experience it ('so long as men can breathe or eyes can see'), and by being the subject of the poem, the beloved's essence is captured and made eternal ('and this gives life to thee').