How to distinct the record when using Group By?

Hallo, I am having the table (look below), which having 4 records. Notice that ColumnA and ColumnB are having the same value, and ColumnC and columnD will have different value.

ColumnA ColumnB ColumnC ColumnD
------- ------- ------- -------
xx      yy      AAA     333
xx      yy      BBB     555
xx      yy      AAA     333
xx      yy      BBB     555

I was trying to select the whole record using Group By query like this:

SELECT ColumnC from TableA GROUP BY ColumnC;

This query only shows me ColumnC but my expectation is to select the whole record not only ColumnC.

UPDATE: My expected output is:

ColumnA ColumnB ColumnC ColumnD
------- ------- ------- -------
xx      yy      AAA     333
xx      yy      BBB     555

May I know how can I do this?

THanks @!