This study aims to determine whether or not heating flaxseeds before consumption can alter the amount of thiocyanate in the blood. Researchers fed 14 rats a diet consisting of 30% flaxseeds for 30 days and then measured the amount of thiocyanate in the blood. Seven of the rats were randomly assigned to eat diets with raw flaxseeds, while the remaining seven were given diets with flaxseeds that were heated at 170°C for 15 minutes.
(a) Briefly explain how you can tell that the study described above is an experiment and not an observational study.
(b) Will this study design allow the researchers to investigate whether or not heating the seeds can actually affect blood thiocyanate levels in flaxseed rich diets? Very briefly explain.