I have:
A1 = "A"
A2 = "A"
A3 = "B"
A4= "C"
A5= "A"

and

B1= "Apples"
B2= "Pears"
B3= "Strawberries"
B4= "Pears"
B5= "Apples"

I want to calculate the following:

For all the occurences of "A" in Column A, I want to count the uniquely
different TYPES of values that are contained in column B.

E.g. in the example above, the answer will be "2", because there are 3 x
occurences of "A" in column A, and these 3 occurences related to 2 occurences
of "Apples" and 1 of "Pears", thus 2 unique strings of data.

Please help.