Answer: A (1:2)
Explanation:
Since there are 12 puppies total and 8 of the puppies are yellow labs, there must be 12 - 8 = 4 black labs. Now, the ratio of black labs to yellow labs is 4:8 because there are 4 black labs and 8 yellow labs. However, we can simplify this ratio by dividing the entire ratio by 4. In this case, we would get (4/4):(8/4), which simplifies to 1:2, which is the answer.