Child benefit form - confusing question

[need_a_tier1]

I was granted ILR in Oct 2011.

I am filling the child benefit form and came across these two questions:

18. Are you subject to immigration control now, or at any time in the last three months? [Y/N]
My Answer - YES

19. If you have been subject to immigration control in the last three months tell us the date your immigration status was granted.
My Answer - Not Sure, Confused!! . Is this the date when ILR was granted?



Can someone please suggest what date I should provide as answer to Q 19:

- Date when ILR granted
- Date when I first came to the UK (on a work permit)

[Casa]

Date ILR was granted.