Question $5$: Set Operations

Suppose you have two HashSet collections groupA and groupB with the following contents:

Set groupA $=$ new HashSetArrays$.$asList$("$Alice$",$ "Bob", "Charlie", "Diana"$))$;

Set groupB $=$ new HashSetArrays$.$asList$("$Charlie$",$ "Diana", "Eve", "Frank"$))$;

Questions:

a$.$ Calculate the union of groupA and groupB and output the result.

b$.$ Calculate the intersection of groupA and groupB and output the result.

c$.$ Calculate the difference of groupA and groupB $($i$.$e$.,$ the elements in groupA but not in groupB$)$ and output the result.