RANGE ROVER TYRE SIZE HELP

[T5AMX]

Hi I have a 2002 TD6 VOGUE

I have just bought some 20" Stormer alloys for it.
What tyre size is the correct one for these as so many garages arnt sure and I don't want to get it wrong with using range rover sport sizes...
im not sure if its the following:
1. 275/40/20
2. 275/45/20
3. 275/50/20
4. Suggestion?????

Any help would be greatly received please

Thanks

[camel_landy]

275/45R20.

275/40R20 is for a Range Rover Sport.

M

[T5AMX]

thanks....