Question: How to create an anti-allergen vacuum cleaner.
Option 0: First decide if you want to make a bag, or bag-less model, then decide if you want to make an upright or cannister model, finally consider what type of allergens you wish to block and address those through appropriate filtering devices.
Option 1: First decide if you want to make a bag, or bag-less model, then decide if you want to make an upright or cannister model, finally consider what type of allergens you wish to block and address those through appropriately placed signs.
Answer: 0