Answer: A) Mr. Sargent bought a sweater for his dog with purple and pink spots.
Step-by-step explanation: an adjective is a word or a phrase that we use to describe or modify a noun. In the first sentence the adjective phrase is "with purple and pink spots" this adjective phrase is modifying the noun "sweater" but as it is, it seems that is the dog who has spots. The correct order of the phrase would be: Mr. Sargent bought a sweater with purple and pink spots for his dog.