I 539 yes 和no的问题不知道怎么回答了，请指教！

8.a. Served in, been a member of, assisted, or participated in any military unit, paramilitary unit, police unit, self-defense unit, vigilante unit, rebel group, guerrilla group, militia, insurgent organization, or any other armed group? Yes  No
8.b. Worked, volunteered, or otherwise served in any prison, jail, prison camp, detention facility, labor camp, or any other situation that involved detaining persons?
Yes   No
最近在给爸爸妈妈申请B2延期，我爸爸退休前在监狱工作（监狱警察，科级吧，普通职位），现在已经退休五年了，不知道这个8a和8b的问题怎么回答，是Yes还是No？

yes and yes?

其实这个可以填NONO