If you were going through the 1099-R interview and indicated that this distribution was for Arkansas, you probably saw a screen entitled "Where Is This Distribution From?". One of the choices is "Employer-sponsored pension plan or qualified IRA". For purposes of this question, yes, the ATRS is considered an employer-sponsored pension plan.
ATRS is a defined benefit plan for public school and other public education employees. It is administered as a "qualified" retirement plan under the provisions of IRS § 401(a). So, on the next screen when you are asked "Was This Distribution From a Qualified Plan?", you will answer "From a Qualified Plan".