Bessie I've only grown two of those on  your list. 
It's not Blizzard. 
20th Ave & Baker Rd. is a tall plant with light green foliage and bloom is similar but has more petals so a possibility, but doubtful
Googling the ones I  haven't grown - Dave's Glacier looks like it has a blush, so no. Mt. Hood is larger (5"), so no. Ferncliff Pearl is  possible, supposed to have dark green foliage. 20th Ave Tradition is a ball and supposed to have a blush so no. Hillcrest Amour is  supposed to have a blush, so no. Center court is larger (6"+), so no.
If the plant has dark green  foliage, I would guess Ferncliff Pearl.
If the plant is tall with light green foliage, I would guess 20th Ave & Baker Rd.
 Edit: After looking  at  a few more photos it looks like Ferncliff Pearl has more pointed florets than yours.
So, I  have no clue. But is was fun  looking at white cut dahlias.π