Count Unique Text String

Please See the attachment sample file.

Cell C5 is having the issue. the value should be 39. How i will tell you.

If you goto to Master sheet and applied filter and select Dental in column C. Keeping the filter goto column K and apply filter and select 0:20 till 0:29 then you will get the values at the status bar i.e. Bottom Left Corner.

I hope i have explained to you what is my problem.