Question

A company wants to test a new brand of dog food that has added omega-3 oils for healthy, shiny coats.

The company selects two groups of volunteers who have dogs as pets. They give each person in both groups a month's supply of dog food. Each bag of dog food is unlabeled. One group is given the dog food with the added omega-3 oils, and the other group is given a brand of dog food without the added omega-3 oils. Both groups are asked to feed their dogs the food the company gave them and report whether they noticed an improvement in their dogs' coats.

A.
The experiment is blinded because the volunteers in both groups are unaware of which dog food they received.
B.
The experiment is blinded because the volunteers in both groups and the company are all unaware of which group received the dog food with omega-3 oils.
C.
The experiment is not blinded because the volunteers in both groups and the company are all unaware of which group received the dog food with omega-3 oils.
D.
The experiment is not blinded because the volunteers in both groups are aware of which type of dog food they received.