Questions about DS 156 - Visit visa for parents

[PVS]

I want to bring my parents here for 6 months through Visit Visa. They applied Green card through my uncle long back and got it approved 2 years back. However they did not send the documents as they did not want to come and settle down in US. Their Green card was cancelled. Do I need to fill in yes to the DS 156 for question number 36?

The question # 36 is?
Has anyone ever filed immigration Visa petition.


1. Can I give an explanation in the application that we cancelled the Green card?

2. Is there a chance they would reject their Visa?

[immihelp]

#36. Yes.
1. Yes.
2. Hard to say.