Answer:
Bolsa.
Step-by-step explanation:
la Bolsa - la Casa - la Puerta - la Ventana
Bag - House - Door - Window
The '' intruder'' in this row would be bag, la bolsa. Why? Because casa, puerta and ventana are parts of each house. They all have one more thing in common -- along with bolsa, they're all feminine nouns, and they're singular.
La bolsa would belong to a row with accessories.