Count Unique Text Values with 2 criterias/condition

Hello everyone! I need some help on my excel spreadsheet. I tried to look for answers to resolve this for the past weeks but I got none that fits my current situation.

In Cell T12, I need to get a total unique text values from "POP-WS Registration column" cells B48-B300 based on these criterias: 1.) it should be tagged as "Closed" in topic status cells G48-G300; 2.) It should be categorize as "Workshop Process Improvement/ Wastes Reduction" in CI topic nature cell I48-I300.

Hope you could help me.
Thanks!