Final answer:
d.Simile. The device of figurative language used in the text is simile, comparing the sweetness of the puppies to sugar.
Step-by-step explanation:
The device of figurative language used in the text is simile. A simile is a figure of speech that compares two things using the words 'like' or 'as.' In the given sentence, the comparison is made between the puppies and sugar, stating that the puppies are as sweet as sugar. This comparison helps convey the idea that the puppies are very sweet and desirable.