SAT Inferences Question

Neurobiologists Laura Cuaya, Raúl Hernandez-Pérez, and colleagues investigated the language detection abilities of eighteen dogs of various ages. The researchers monitored the brain activity of Maverick (a 117-month-old border collie), Mini (a 126-month-old mixed breed), and other dogs while the animals listened to three recordings: one of The Little Prince being read in Spanish, the second in Hungarian, and a third made up of short, randomly selected fragments of the first two, scrambled so that they didn't resemble human speech. Each of the dogs was familiar with either Spanish or Hungarian, but not both. The team concluded that the younger the dog, the worse it may be at differentiating between familiar and unfamiliar languages. Which finding from the study, if true, would most directly support the team's conclusion?