D-156/D157 question

[achopra]

1. So my mother who is less than 55 yrs of age has to fill a D-156 and a
D-157?

2. In D-156 if she has been refused 4 times and don;t know the reasons for 3 times but the last one she got a refusal letter..how does she fill up the section where they ask whether you have been rejected a US visa before...
Where and When? Does she have to mention all 4 times ?

3. How far back does she have to go to mention all the refusals?
Is it one year or more further back?

please reply.
A

[immihelp]

1. Only DS-156.

2. She has to mention all 4 times.

3. There is no limit how far. She has to mention all.