Answer:
C). Hyperbole.
Step-by-step explanation:
Hyperbole is illustrated as the literary device that offers an overstatement or acute exaggeration to highlight a specific idea or point. It helps the author to create a splendid and distinguished effect in order to emphasize a particular point.
As per the question, the literary device employed by Spenser in this excerpt from his 'Sonnet 9' would be 'hyperbole' as the poet exaggerates the description of eyes by saying 'powerful eyes....lighten...dark sprite' and contradicts it by describing it as 'resemble ...image of goodly light', 'shine by night' that helps emphasize the beauty and gleam of his beloved's eyes which however is contradictory as the words 'dark' and 'goodly' proposes a self-contradiction. Thus, option C is the correct answer.