Final answer:
The initial step to identify children at risk for a disability is to conduct developmental and behavioral assessments, rather than considering socioeconomic factors or school size, as these are more comprehensive indicators for early detection of possible disabilities such as ASD.
Step-by-step explanation:
The first step in the process to find out which children are at risk for a disability would involve evaluating factors that are known to influence development. While socioeconomic status and family background play a role, for conditions such as autism spectrum disorder (ASD), where geographical location of diagnosed children can provide clues about environmental factors and challenges associated with diagnosis, it might not be the most immediate concern. Instead, initial developmental screening practices such as standardized tests during preschool and kindergarten years focus on assessing the child's developmental milestones and behaviors that could indicate a risk for learning disabilities or social communication disorders. Therefore, the correct answer for the initial screening step would not revolve around the number of school-age siblings, the socioeconomic status, the age of entry into kindergarten, nor the school's attendance figures. It would instead be focused on developmental and behavioral assessments that can indicate whether a child should be referred for further diagnostic evaluation.