Read the following paragraph and answer the question that follows:

Empirical observation told us years ago that goats were slowly becoming the new dog, and according to a new study, they are truly qualified to be man’s best friend. The Royal Society released heart-warming research showing that just like humans, goats have no desire to interact with people who come off as angry or upset, and that they’re much more attracted to those with big smiles plastered across their faces. When 12 males and 8 females were released into a pen decorated with images of happy and angry humans, the scientists learned that goats can “distinguish between happy and angry images of the same person,” and in general, they prefer their humans to be happy.

Which of the following statements is definitely true according to the passage?