Conflicting info about picking seats on Virgin Flights...

Hi all,
I booked a direct flight with Delta back in July, ready for a flight May 19th to Vegas from Gatwick....
Its a codeshare flight, so were on a Virgin plane.....
My delta booking shows and has always shown that i can select seats from 18th Feb, no mention of charge...
Do you reckon:
A: Seat selection is free for me because of it being a Delta booking
B: I can book seats 90 days early because its a Delta booking?
I booked a direct flight with Delta back in July, ready for a flight May 19th to Vegas from Gatwick....
Its a codeshare flight, so were on a Virgin plane.....
My delta booking shows and has always shown that i can select seats from 18th Feb, no mention of charge...
Do you reckon:
A: Seat selection is free for me because of it being a Delta booking
B: I can book seats 90 days early because its a Delta booking?