Mаriа is mоving frоm elementаry schоol, where she was comfortable, into the sixth grade in Riverside Middle School, and she is a little uncertain about it. In order to help make the transition, Maria's mother drives her to school the first few days. Maria's mother drops her off the first day, and Maria waves to her mother as she walks toward the school. Mrs. Rodriguez greets her at the entrance of the main building, smiles, and shakes her hand. Seeing Mrs. Rodriguez smile reassuringly, Maria relaxes and feels better. During the first week, Mrs. Rodriguez greets Maria each day with the same reassuring manner. Now Maria jumps out of the car and is cheerful about running into the school when her mother drops her off. Consider this a case of classical conditioning with the conditioned response being Maria's cheerfulness when she runs into Riverside Middle School, and identify the best description of each of the following: The unconditioned stimulus would be: