Which combination of early signs can indicate autism spectrum disorder in preschoolers?

• A. Frequent tantrums and preference for being alone.
• B. Normal social interaction but late walking.
• C. Persistent deficits in social communication and restricted, repetitive behaviors; no babbling by 12 months; no words by 16 months; no pretend play by 18 months.
• D. High vocabulary development but poor punctuation.

Answer: (C)

The main idea here is recognizing the two core clusters of early autism signs: persistent difficulties with social communication and interaction, together with restricted, repetitive behaviors or interests. When these patterns appear alongside specific developmental language delays, they strongly indicate autism risk in the preschool years.

This description fits best because it explicitly states persistent deficits in social communication and interaction, plus restricted, repetitive behaviors. It also provides concrete milestones that are missing: no babbling by 12 months, no words by 16 months, and no pretend play by 18 months. These early language and play delays, occurring alongside social-communication challenges and repetitive behaviors, are classic red flags that warrant further screening and evaluation.

Other descriptions don’t capture that combination. Frequent tantrums with a tendency to be alone lacks the clear, enduring social-communication and repetitive-behavior pattern. Normal social interaction with late walking points more to a motor milestone delay than to autism. High vocabulary with poor punctuation doesn’t address the social-communication deficits and restricted behaviors that define ASD.