Answer:
The researchers would find that: A. The child's heart rate accelerates
Step-by-step explanation:
According to Jerome Kagan's research, inhibition is a trait where a child expresses higher levels of activity and shows a higher level of distress when placed in a new environment or around something unfamiliar.
Children like the one described in the question would therefore be more likely to have an accelerated heart rate when they are left alone in a room.