You Decide to Follow the Development of the Human Gut

Multiple Choice

You decide to follow the development of the human gut microbiota over time by sampling the solid waste of infants from birth to 24 weeks old. Which of the following setups minimizes the sources of variation in your experiment?

A) Sample three infants from three different families that are 1 day old, three infants that are 1 week old, three infants that are 2 weeks old, and so on.
B) Sample three infants from three different families the day they are born, when they are 1 week old, 2 weeks old, and so on.
C) Sample identical triplets from a single family when they are 1 day old, 1 week old, 2 weeks old, and so on.
D) All of the experimental designs described here have the same level of variation.