A 15-month-old boy is brought to the office for a well-child visit. His mother reports that he does not yet speak any words and does not respond when she calls his name. He can pull to stand and cruise along furniture but does not walk independently. Physical examination shows normal growth parameters. He makes limited eye contact and does not wave bye-bye. The physician reviews standardized developmental screening results indicating delays in both language and social domains. Which of the following screening timelines and actions is most appropriate for this patient? Age Screening Type Action if Delay Identified Key Red Flags 9 months General developmental Refer to early intervention (Part C) No babbling, poor social engagement 18 months General + autism-specific Immediate referral to early intervention + audiology No single words, no pointing, no imitation 24 months Autism-specific Immediate referral for autism evaluation No two-word phrases, loss of skills 30 months General developmental Refer to early intervention if not improving Persistent language or motor delays