C# how can I preserve data between class instances?

Question

Apologies for the vague title, but I am not really sure how else to explain it.

Given Class A, B and C.

If Class A contains a List, how can I preserve the da

Answer 1

Use static as defined here: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/static

Then you will be able to access the class properties instead of instance properties.