IHT Treatment of Rights to Occupy

I would be grateful for any thoughts on the IHT treatment of the following scenario. Assume A dies leaving B&C joint rights to occupy a property. B then dies leaving C as the sole occupant. What would the IHT treatment of the property be after B’s death? Would C have an IPDI in 50% of the property value (the IIP they were deemed to take following A’s death) with the other 50% being relevant property? Or would C be deemed to have a qualifying interest in possession in the entire property? Thanks

James Daynes
Tees Law