Queries :: Update Query On Multivalue Field

I have a multivalue field containing values of A,B,C and D with primary IDs of 1,2,3 and 4 in that order.

If I was to run:

Code:
UPDATE Table
Set Table.Multivalue.Value = 1
WHERE Field 1 = "True" AND Field 2 = "True";

Then run

Code:
UPDATE Table
Set Table.Multivalue.Value = 2
WHERE Field 1 = "True" AND Field 2 = "True";

Will I have a Multivalue field as A,B or just B? I would like it to be A,B but I have my doubts as to whether this would work.