A new pet food product for small dogs has been developed to help with tooth decay.Fifty-two dogs participate in the study. Each dog owner picks a card from a standard deck out of a hat. If the card is red, their dog will be in the treatment group. If the card is black, their dog will be in the placebo group.

Which experimental design was used?

• Matched-Pair Design
• Case-Control Design
• Randomized Block Design
• Completely Randomized Design