SUMPRODUCT Multiple Criteria with Distinct Values

Hi everyone, I am hoping to get some assistance with a SUMPRODUCT formula with multiple criteria.

In the attached example s/sheet I am trying to count the number of distinct ‘Tests’ in column B (= 8) that also meets the adjacent ‘Result’ criteria (= Result 1), in column C (answer = 7 which I have manually counted to illustrate the requirement).

The independent components of my formula seem to work:

• Counting distinct Values only (case insensitive) in column B
• Counting Test results that = “Result 1” in column C

I need help with combining the formula.

Thanks in advance,
KJ