Final answer:
The line that contains consonance in 'Nothing Gold Can Stay' by Robert Frost is 'Her hardest hue to hold.' Consonance adds musicality and rhythm to a poem. So the correct answer is Option B.
Step-by-step explanation:
Consonance is the repetition of consonant sounds at the end of words. In the poem 'Nothing Gold Can Stay' by Robert Frost, the line that contains consonance is: 'Her hardest hue to hold.' The 'd' sound in 'her hardest' creates the consonant repetition. Consonance adds musicality and rhythm to a poem, enhancing its overall effect.