I don't know, toss a coin.
How could I possibly know better than you?
How many of these units do you have?
Try Googling, look at other datasheets, what's the most common pin-out?
Perhaps you could connect one up with the lowest voltage it will work at with a small resistor in series to llimit the current. If it doesn't work, change the connections then if it still doesn't work try another device. If you've only got one device then it's hard luck as you've got a 50% chance of destroying it.
I would guess option 1 so perhaps you should try it first but I can't promise anything.