Multiple choice fields

I going to import data into Knack using Zapier, some of that data will be appreviations eg Loc, Nat.

So for the multiple choice field in Knack I will create choices of Loc and Nat.

My question is what happens after I have imported my data and I want to change those multiple choice fields to Local and National will it just leave the existing data as is i.e Loc, Nat. or does something else happen

 

thnx J x