A group of experimenters has 30 hummingbirds in a large container and needs to assign 10 to each of the three groups labeled A, B, and C for an experiment. They can capture the hummingbirds one at a time when the hummingbirds enter a side chamber in the container that is baited with food. Which of the following methods is MOST likely to result in three comparable groups of 10 hummingbirds each? Label the first 10 hummingbirds caught as group A, the second 10 caught as group B, and the third 10 caught as group C.

Write the letters A, B, and C on separate slips of paper. Pick one of the slips of paper randomly and assign the first 10 hummingbirds caught to that group. Pick another slip and assign the next 10 hummingbirds caught to that group. Pick another slip and assign the next 10 hummingbirds caught to that group.

When each hummingbird is caught, roll a die. If the die shows an even number, the hummingbird is labeled A. If the die shows an odd number, the hummingbird is labeled B. When 10 hummingbirds have been labeled A and 10 have been labeled B, assign the remaining 10 hummingbirds to group C.

When each hummingbird is caught, roll a die. If the die shows a 1 or 2, the hummingbird is labeled A. If the die shows a 3 or 4, the hummingbird is labeled B. If the die shows a 5 or 6, the hummingbird is labeled C. Repeat this process for all 30 hummingbirds.

Place each hummingbird in its own numbered container (numbered from 1–30) in the order that it was caught. Write the numbers from 1 to 30 on slips of paper, put the slips in a jar, and mix them well. Pick 10 numbers out of the jar. Assign the hummingbirds in the containers with those numbers to group A. Pick 10 more numbers for group B. Assign the remaining hummingbirds to group C.