💡 Detailed Explanation
The clerk explains four air purifiers: A (Compact/Quiet), B (Deodorizing for pets), C (Humidifier combined), D (Smart app connection). The couple discusses their needs: they recently got a dog and care about the pet odor in the living room. They already have a humidifier, ruling out C. They decide to focus on solving the pet odor problem rather than fancy app connectivity (D). They choose the pet-specialized deodorizing model (Type B). Thus, the correct answer is the pet deodorizing model.