457B plan classification

[Michiganma]

State of Michigan wants me to indicate if funds came from a 457B plan.  Recently did an conversion to ROTH from what is now an IRA but was initially set up in a 457B.  Upon retirement my 457B was rolled into IRA accounts.  I am wondering if classification is based on current IRA designation or 457B classification due to the fact that the funds were accumulated initially under that 457B plan?  Makes a big difference on how the funds are taxed.  Even if I class it as a conversion, if the 457 box is checked it changes the full amount to taxable.