CGU

Whic statemnet is true according to IAS36

1) A cash generating unit is the smallest identifable group of assets for which individual cash flows can be identifies and measured.

2) when considring the impairement of CGU, the calculation of the CA and the RA does not need to be based on the exactly the same group of net assets.

3) When it is impossible to calculate the recoverable amount of single asset then that of its CGU should be measured instead

I have done 1 and 3. but i don’t know the answer