Having this example sheet (just sample data)
Column-A Column-B Column-C
1 claudia claudia@gmail.com SOLD
2 claudia claudia@gmail.com CONTACTED
3 natalia natalia@gmail.com CONTACTED
How to use FILTER to filter row 3, that is to say: rows where colum-c is CONTACTED but excluding duplicated rows where one of the duplicated instances has "SOLD" within column-c.
Definition of "duplicate": same email (column-b)