Answer:
The cat's purr was a soft lullaby
Step-by-step explanation:
The other answers are just descriptions of the animals aka adjectives, which are facts e.g the bear is big and brown is a factual way on describing a bear while the cat's purr was a soft lullaby is a figure of speech which is not literally applicable. Others could describe it differently, by using metaphors such as cat's purr was a lovely melody but factually and adjectival we could say about the cat that it's purr was nice.