Concept:Autism Spectrum Disorder (ASD) involves challenges in social communication, sensory processing, and repetitive or restricted behaviors.
Explanation:Children with autism often show repetitive actions, such as repeating words, lining up objects, or following strict routines.
They typically struggle with social interactions and verbal communication.
Hyperactivity is not a defining feature of autism, though it may occur in some children.
An urge for social interactions is usually reduced, not increased.
Thus, among the given options, repetitive behavior is the most characteristic symptom.
Answer:C. repetitive behavior